Javascript replace case insensitive What language are you using? A standard way to do this would be something like /([Ff][Oo]{2}|BAR)/ with case sensitivity on, but in Java, for example, there is a case sensitivity modifier (?i) which makes all characters to the right of it case insensitive and (?-i) which forces sensitivity. replace(stringReg, 'javascript'); Depending upon our comfort we can use either of the regular expression ways. log(output); In this JavaScript replace example, notice how a case-insensitive replacement should be applied. Many of us use this rep Mar 11, 2012 · Assuming you want the whole regex to ignore case, you should look for the i flag. */i string. Case insensitive matching and replacing while respecting casing of source 在上述例子中，我们定义了一个replace_case_insensitive()函数，使用re. s Nov 15, 2024 · The i following g makes the replacement case-insensitive, demonstrating the versatility of regular expressions in string manipulations. Sep 26, 2012 · The String. Whether processing user input, manipulating data, or modifying displays, I utilize this handy string method on a near-daily basis. Example 2: Case-Insensitive Replacement const text = "javaSCRIPT JavaScript"; // all occurrences of javascript is replaced Dec 23, 2020 · JavaScript's replace already has the functionality of doing a case-insensitive search while also retaining the original case of a capture group, e. search(/best/i); alert( Feb 18, 2020 · Just an alternative suggestion: when you find yourself reaching for "case insensitive regex", you can usually accomplish the same by just manipulating the case of the strings you are comparing: const foo = 'HellO, WoRlD!'; const isFoo = 'hello, world!'; return foo. Replacing Specific Parts Using Capture Groups: Using capturing groups in regular expressions allows you to target specific parts of the matched string. ignoring case, you can do something as simple as this: var initialText = "This is a Test"; initialText. g With this flag the search looks for all matches, without it – only the first match is returned. toLowerCase() + "\\b", 'g'), "value to replace"); Now this is a CASE SESITIVE Replace i want to make it CASE INSENSITIVE. An overview of strings in JavaScript To start, a quick string refresher. Here is an extension method that implements a case-insensitive version of String. Javascript case insensitive replace all: # The above method will not replace the case-insensitive string. 5. Read more about regular expressions in our: RegExp Tutorial; RegExp Reference; See Also: The replaceAll() Method - replaces all matches Jun 25, 2022 · In Javascript the two previous examples are great, now let's complete using the replace() function to also change the string with a case insensitive in the original string. Using the replaceAll() Method. An example of that Java regex modifier can be found here. prototype. An example is shown in the later part of this tutorial to perform the case-insensitive replacement. The replaceAll() vs the replace() Method - What's The Difference? The difference between the replaceAll() and the replace() methods is that replaceAll() performs a global substitution straight out of the box. Apr 1, 2024 · In this example, the replace() method is used to replace the word 'World' with 'JavaScript'. You can remove the i flag if you don't need to ignore the case. If you can show a quick example of the tag using the parameter or method that makes Mar 3, 2024 · In this example, we used the i flag to perform a case-insensitive search for the l character in the string and replaced it with an underscore. javascript replace all with case insensitive and keeping correct case in original string. Set the ignore flag on the first argument. To enable case-insensitive replacement, use the i flag instead. […] Jan 4, 2016 · The (?i) is the case-insensitive flag: starting from the point inside your regex where it is placed it makes all the character class containing letter e. The i flag allows us to perform a case-insensitive search in the string. Nearly all regex engines support it: /G[a-b]. replace(/is/ig, 'as'); console. Aug 25, 2013 · Case Insensitive javascript replace regex taking account word boundary. When using the replace() method, specify this modifier to replace all matches, rather than only the first one. It takes two parameters: the . Replace("test","It works!", true, null); The last parameter is a boolean that indicate to ignore case sensitive or not, in this case as we are ignoring it, it will replace the text even when the original text starts with capital letter. However when I use the “find & replace” function to change the color of the text being searched to blue, the “find & replace” function is case Mar 19, 2024 · The JavaScript `replace()` method is a built-in function that performs a case-sensitive search to replace values in a string. Using replace() - Removes First OccurrenceWe replace "G" with "" using replace() method [GFGTABS] JavaScript let s = Jun 2, 2013 · Javascript does not support modifier spans so you cannot have the beginning be case insensitive and the rest of the pattern case sensitive. Jun 27, 2017 · So as you can see from the images below, I’m using the input to search for questions & answers that contain the word “Star” or “star”. function replaceCaseInsensitive(str, find, replace) { let result = ""; let findLower = find. m - Multi Learn how to perform case-insensitive comparisons in JavaScript using toLowerCase(), toUpperCase(), and regular expressions with the i flag. replace() Method. 18. 29. replace(typedVal, "<b>" + typedVal + "</b>") the problem is that if I have in the innerHTML e. Feb 27, 2024 · We used the g flag to replace all occurrences of the regex in the string and not just the first occurrence. Feb 15, 2025 · The i flag indicates that case should be ignored while attempting a match in a string. A list of useful modifiers: g - Global replace. Regular expressions, usually simplified as “ regex “, improved this functionality by allowing you to perform advanced pattern matching and replacement. replace() will only replace the string if the text contains exactly the word "apple" but if i search for "Apple", the search still works but in that case html. ,In this syntax, the replace() method find all matches in the str, replaces them by the newSubstr, and returns a new string (newStr). Similar to the . /i makes the regex match case insensitive. The replacement should work with case insensitive characters (like the string foo in the sentence My Foo bar). Replace text but keep case. This chapter describes JavaScript regular expressions. replace() does not works since the string contains word "apple" not "Apple". Using Javascript replace case insensitive is relatively straightforward. Net Core 2. Use the jQuery text function to get its text. Example 3: Case-Insensitive Replacement const text = "javaSCRIPT JavaScript" // the first occurrence of javascript is replaced let pattern = /javascript/i; // case-insensitive search let new_text = text. I want to highlight a single string in a sentence. Replace Multiple Occurrences Without a Regular Expression. Jul 30, 2009 · This means that your replace will replace all copies of the matched string with the replacement string you provide. * Example, search for all 'a' (case insensitive) and replace it with 'a * someString' if it was lowercase. txt. how can i remove case sensitivity of html. log(new_text) // JS JavaScript // all occurrences of javascript is replaced pattern = /javascript/gi; // case May 29, 2012 · @mowgli Yes, that's right. repalce in my code? W3Schools offers free online tutorials, references and exercises in all the major languages of the web. Share Mar 23, 2012 · To indicate a case-insensitive search, use the i flag. RegExp in JavaScript with Case Sensitive Modifier. /m enables “multi-line mode”. JavaScript replaceAll case-insensitive search Jan 26, 2010 · There are two ways for case insensitive comparison: Convert strings to upper case and then compare them using the strict operator (===). The i flag makes the search case-insensitive. To replace all instances, use a regular expression with the g modifier set. highlight() { const re = new RegExp(this. Case insensitive matching and replacing while respecting casing of source Jun 9, 2011 · javascript replace all with case insensitive and keeping correct case in original string. [a-z] to matches also [A-Z] (and viceversa). # Replace all occurrences of a String using split() and join() This is a two-step process: regex - matching a string with the first occurrence case insensitive 3 PHP - preg_match - How to match a string upper/lower case with anything before or after it? Jan 1, 2020 · Use String. The code for this article is available on GitHub. This is no problem for me: var re element. Replace the text Nov 14, 2023 · Strings are the duct tape of programming – we use them for everything! Let‘s learn how the versatile replace() method can help us manipulate strings in JavaScript. replace(/regex/g, "rocks"); console. replace(/hello/g, 'hi'); May 25, 2014 · Custom Javascript replaceAll() using prototype with Case Insensitive Matching! Introduction I was using the regex replace all, but found out it had errors replacing certain reserved characters without escaping them first. log (updated) //"Java is Java!" replaceAll() Method The replaceAll() method replaces all occurrences of a substring in a string and returns the new string: Oct 12, 2023 · Verwenden Sie die String-Methode localeCompare(), um einen case-insensitive Vergleich in JavaScript durchzuführen Während die obige Methode eine einfache Antwort gibt, funktioniert sie möglicherweise nicht gut, wenn die Strings Unicode-Zeichen enthalten. log(result); // "rocks rocks ROCKS!" Also note that matching is case-sensitive by default. var stringReg= new RegExp(stringtoreplace, 'g'); targetstring = targetstring. replace() will only replace the first matched pattern it finds unless you use regex with the g flag: const campString = 'paidCodeCamp is awesome. 1 • 7 years ago • 0 dependents • MIT published version 1. Case-insensitive string replace-all in JavaScript without a regex. However, this method is always case-sensitive. It is great to… Jul 18, 2014 · is there a way to replace a word with another within a page but case-insensitive so that it replaces every word, but also keeps the origianl case of the word it has just replaced? I am currently using this method of which is case-sensitive. AA it will not work since the value is in upper case,how can I overcome it? I cannot use the following since I want to keep the value with the original case so in this example upper case Dec 11, 2024 · Hello students! After teaching JavaScript for over 15 years, I want to share my deep knowledge on one of the most useful but often misunderstood topics – regular expressions (aka regex). How can i accomplish this? Aug 8, 2017 · The text pattern can be used to make JavaScript RegEx replace and search text. 0. replace() is regexp-based; if you pass in a string as the first argument, the regexp made from it will not include the ‘g’ (global) flag. Oct 4, 2023 · Learn how to ignore case sensitivity in programming using regex. Here’s an example of how it can be used: var modifiedString = string. Case insensitive matching and replacing while respecting casing of source string. var input = "DNA deoxyribonucleic acid"; var output = input. . The result is that the first instance of "java" is replaced with "JavaScript". replace() returns a new string, and the original remains the same. sub()函数进行替换操作，并传递了re. Make javascript regex case Jan 24, 2025 · Regular expressions are patterns used to match character combinations in strings. My function that produces the search substring uses the innerHTML property May 5, 2024 · How to Use Javascript Replace Case Insensitive. You can abstract it into a function as Then I search using a lower case version of the query string or do a case insensitive regexp. replaceAll() method: May 7, 2022 · Summary: in this tutorial, you’ll how to use JavaScript String replace() method to replace a substring in a string with a new one. *", "i") Check the documentation for your language/platform/tool to find how the matching modes are specified. Jan 8, 2014 · Case Insensitive javascript replace regex taking account word boundary. i - Case insensitive replace. Dec 28, 2011 · I am writing the replace function in javascript taking account into word boundary. let str = " Hello World, Jan 26, 2019 · #javascript This video talks about the replace function in javascript where we can replace all the occurrences of a string in a text. May 15, 2012 · Javascript replace not replacing case insensitive even with the tag applied Hot Network Questions Can you construct a 3x3x3 cube using 9 red, 9 green and 9 blue unit cubes such that there is no “line” of 3 unit cubes that are all the same color? Case-insensitive accent folding function to replace an accented character with its unaccented counterpart. toLowerCase() === isFoo. Feb 18, 2022 · Specify the /g (global) flag on the regular expression to replace all matches instead of just the first: string. Then use the resulting found start index in the main string, plus the length of the query string, to highlight the query string within the result. Python W3Schools offers free online tutorials, references and exercises in all the major languages of the web. Replace all instances of the matched string in the provided text. Normally it would be like this: var string="Stackoverflow is the BEST"; var result= string. The only thing you need to do is add the “i” parameter when using the regular expression object. The replace method is a part of the String object's prototype. 2. match() method, . Jul 4, 2017 · javascript replace all with case insensitive and keeping correct case in original string. Jan 4, 2021 · The best part is that . Replace all instances of the matched string, ignoring differences in case. You can safely build a regexp object from an arbitrary string provided that you escape that string first . Step-by-Step Guide to Replacing All String Occurrences Understanding the String. Discover best practices for case insensitivity in JavaScript, Python, and PHP. Then you defined the string "JavaScript" as the replacement. escapeRegExp escapes all special regex characters, although you really only need to escape (and ) with your inputs, it's better to escape everything in case you add new emoticons that use other characters like :] or something later on. Conclusion. ,The following shows the syntax of the replace() method:,Home » JavaScript Dec 12, 2004 · So to do the search and replace correctly I need to find a way to make the replace function case in-sensitive. toLowerCase(); Sep 13, 2024 · JavaScript `string. Feb 14, 2017 · There's indeed a "flags" method in String. Whether you‘re just getting started with JavaScript or have been coding for years, understanding regexes will make you a more efficient and capable programmer. May 2, 2019 · const str = 'JavaScript is JavaScript!' const updated = str. var str Mar 30, 2011 · When a change a few of these properties and pass back the json, the web service now expects camel case (again, as per our naming convention for method parameters) instead of the pascal case initially returned. searchValue, 'gi'); // global, insensitive const newText = name. It’s a one-liner, making it highly efficient and readable for simple replacements. Covering popular subjects like HTML, CSS, JavaScript, Python, SQL, Java, and many, many more. For example: $("#element"). replace() with a regexp object that has the i (case-insensitive) flag set. By passing re. Here’s the step by step process: Find and select the element containing the text. replace(/_/g, ' '). The replace() function in JavaScript is a powerful tool for string modifications, enabling developers to replace substrings based on simple matches or complex patterns. Whenever you need to do a case-insensitive replacement, add an i (ignore case) flag to your regular expression like this: const myText = " Walker walked into a shop while walking home. match("G[a-b]. The StringComparison has the OrdinalIgnoreCase property and it treats the characters in the strings to compare as if they were converted to uppercase (using the conventions of the invariant culture) and then it performs a simple byte comparison and it is independent of language. innerHTML. replace(/#/g, '') To replace one character with one thing and a different character with something else, you can't really get around needing two separate calls to replace. The search is case insensitive which is great! The question is displayed in both scenarios. g. IGNORECASE as a flag, it matches the target string regardless of case. If you need to replace all instances of a string, you can use the . Best Practices for Using If you replace a value, only the first instance will be replaced. replace(new RegExp("\\b" + wordList[i]. replace(new RegExp('this', 'gi'), 'that'); Replace Without Considering Uppercase/Lowercase. It's just taking the flags out of your replace function and converting them into flags for a regex. Dec 7, 2020 · There are only 6 of them in JavaScript: i With this flag the search is case-insensitive: no difference between A and a (see the example below). innerHTML = element. The replace() method can be used to replace or remove the specific character from the given string. 1. NEW - Check out our NEW program SheCodes Bootcamp - and become a developer in just 4 months! Mar 8, 2015 · /* * Replace all instances of a letter (case insensitive) with itself + add some string. Apr 22, 2015 · Case insensitive string replacement in JavaScript? javascript replace all with case insensitive and keeping correct case in original string; Case insensitive replace all; EDIT: From some of the answers, some clarifications — I didn't spec these originally, but they are typical search/replace behavior: Feb 8, 2016 · Also, note that the replace method is case-sensitive. text(). Replace that supports StringComparison. Make Javascript regular expression case insensitive. See those examples in the example section below for detail. This works also for a single letter a (matches a and A) or sequence ab (matches ab,Ab,aB,AB). Apr 14, 2025 · JavaScript supports the following modifiers, a subset of those supported by Perl: /g enables “global” matching. Jun 8, 2021 · To do a Case insensitive replace all with JavaScript string, we can use a regex to do the replacement. The search is case sensativity and only replaces the first matching string, but case-insensitive and replacing all matching strings can also be done. This is not very efficient, as it'll replace previous matches with itself, but it'll work. Feb 8, 2024 · To replace the text of any element using jQuery use the text function together with the replace function of JavaScript. 3. document. Replace() method is useful for easily replacing all occurrences of a substring with another substring. Nov 27, 2013 · Suppose i search for word "apple", html. To indicate a multi-line search, use the m flag. startsWith(findLower)) { result += replace; index += find. # You can also pass a string to the replace() method. replace()` useful cases Case-insensitive Replacement You can make the replacement case-insensitive using the i flag. W3Schools offers free online tutorials, references and exercises in all the major languages of the web. For example, you can look for a case-insensitive JavaScript RegEx match. IGNORECASE标志。 这样，不论原字符串中的”python”是大写还是小写，都会被替换为”Java”。 Example 4 - Global and Case-insensitive Search. Case Sensitivity in JavaScript replace() Method; It's important to note that the replace() method is case-sensitive. Introduced in ECMAScript 2021, the replaceAll() method offers a straightforward way to replace all occurrences without needing to use a regular expression. These patterns are used with the exec() and test() methods of RegExp, and with the match(), matchAll(), replace(), replaceAll(), search(), and split() methods of String. log(str) Feb 2, 2019 · This video talks about the replace function in javascript where we can replace all the occurrences of a string in a text. replace("Hi", "Bye"));. To search for the word “apple” in a case-insensitive manner, the RegEx pattern would be “/apple/i”. length; } else { result += str[index]; index++; } } return result; } // Example usage let Mar 1, 2024 · To do a case-insensitive string replacement in JavaScript: Call the String. Pattern matching using string methods: Use the "search" string method for case insensitive search. Approaches: We are going to discuss two different approaches for creating a case-insensitive regular expression pattern in JavaScript. Replace(). To perform a "sticky" search, that matches starting at the current position in the target string, use the y flag. Many of us use this replace method wrong while writing code. Case-insensitive matching is done by mapping both the expected character set and the matched string to the same casing. replace() method method on the string. body. Its popularity speaks for itself: With advanced regular expression matching, replace() eliminates […] Jul 28, 2022 · The regular expression /dogs/gi will match all instances that contain that substring and make the replacement case insensitive. You can not use the query string in the result since its case is not determinate. replace (/ javascript / gi, 'Java') console. The replaceAll() method is case sensitive. An alternative non-regexp idiom for simple global string replace is: Dec 4, 2024 · Your All-in-One Learning Portal: GeeksforGeeks is a comprehensive educational platform that empowers learners across domains-spanning computer science and programming, school education, upskilling, commerce, software tools, competitive exams, and more. replace(/value to be found/gi,"replacement value")"; where "g" represents global Replace, "i" means ignore case. The ignore flag does a case-insensitive search in the string. Dec 12, 2004 · How do I make a Javascript replace search case insensitive? My original string contains tags which are mostly lowercase. – Boris the Spider Commented Jun 2, 2013 at 10:14 Nov 4, 2021 · In JavaScript, the replace() function can use regular expressions to replace strings in a case-insensitive manner. If the word “javascript” was used in the replace method, the source string would have remained the same. This article covers the basics, including the regex case insensitive flag and character class. toLowerCase(). Aug 9, 2011 · Case Insensitive javascript replace regex taking account word boundary. m Multiline mode (covered in the chapter Multiline mode of anchors ^ $, flag "m"). The result is a new string 'Hello, JavaScript!'. By mastering both the basic Dec 11, 2024 · As a professional JavaScript developer and mentor with over 15 years of hands-on experience, few methods surprise me more with their versatility than replace(). replace( regex, "<b>$1</b>" ); Feb 14, 2017 · javascript replace all with case insensitive and keeping correct case in original string. toLowerCase(); let index = 0; while (index < str. var regex = new RegExp( '(' + word + ')', 'gi' ); return line. This option is essential if you want to replace all occurances of the search string (which is usually what you want). If the regex is Unicode-aware, the case mapping happens through simple case folding specified in CaseFolding. In JavaScript, regular expressions are also objects. This means that it will not replace a string if the case does not match. You can also use a string as the first argument of the replace() method. Case Insensitive Global Search; By Jul 2, 2014 · Case Insensitive javascript replace regex taking account word boundary. For example if I had a typo in my code and actually wrote Yellow with a capital instead of all lowercase the string replace a replacement string and the string replace a new Oct 11, 2012 · Case Insensitive javascript replace regex taking account word boundary. text($("#element"). Case insensitive matching and replacing while respecting casing of source Feb 2, 2019 · This video talks about the replace function in javascript where we can replace all the occurrences of a string in a text. Case insensitive search with case sensitive replace. javascript replace all with case Nov 26, 2024 · We are given a string and the task is to remove a character from the given string. 7. tylerjpeterson • 1. Scenario: case-insensitive search box on list of items, partial match on string should be displayed highlighted but keeping original case. 0 and higher has native method String. replace ( / walk / gi , " Jogg " ); Jun 6, 2023 · Here, to create a case-insensitive regular expression, we have added the “i” flag after the expression. Start with specifying the string to be modified. replace, but it is non-standard, thus unreliable. In the following example we will perform a global and case-insensitive match, and the word Microsoft will be replaced each time it is found, independent of upper and lower case characters: String. The best approach would be to make a "polyfill" method that selects an appropriate option. 1 , 7 years ago 0 dependents licensed under $ MIT Dec 19, 2024 · The i flag makes the pattern case-insensitive. substring(index). To perform the case-insensitive replacement, you need to use a regex with a i switch (case-insensitive search). For instance, we can write: const str = 'This iS IIS'. The syntax is "string. Mar 4, 2025 · How to Use JavaScript replace() with Regular Expressions Case-Insensitive Replacement: To make your search case-insensitive, use the i flag with the regular expression. Oct 3, 2013 · Javascript | case-insensitive string replace. Make Javascript regular expression Notice the gi modifier; g stands for global, and i stands for case-insensitive, ensuring all instances are replaced regardless of their case. Apr 5, 2025 · This method utilizes Python’s re module to perform a case-insensitive substitution directly. Nov 23, 2024 · How can you replace all case-insensitive occurrences of a substring in JavaScript? Example Scenario; Solution 1: Using Regular Expressions; Solution 2: Extending String Prototype; Solution 3: Implementing a Custom Case-Insensitive Replace Function; Alternative Ways; Feedback and Comments Dec 27, 2023 · In this comprehensive guide, we will deep dive into performing case-insensitive string replacement in JavaScript – an approach that can mitigate case-sensitive risks in Linux when configured properly. blog = blog. innerHTML = document. It provides a brief overview of each Aug 8, 2023 · JavaScript string replace is a method that enables you to replace circumstances of a specified substring or pattern within a string with a new substring. If it was a capital than replace it with 'A someString' */ This is my code (Sorry its all in a string, has to be for the webview). replace(/(dna)/ig, "***$1***"); console. Strings represent text and are created by enclosing characters inside single or double quotes: let greeting […] Dec 19, 2009 · You need the i to make the search case insensitive and the g to make sure you replace all occurrences. const myReplacementResult = myText . replace(re, `<b>$&</b>`); return newText; } the $& is the matched text with case I'm trying to get a case-insensitive search with two strings in JavaScript working. length) { if (str. Learn to work with JavaScript strings without hassle! 🎁 Airdrop Season 7 is LIVE - Answer Fun Questions to Earn $30K Prize Pool Rewards . Case insensitive matching and replacing while respecting casing of source Aug 30, 2024 · Like before, we need the g global flag to replace all matches instead of just the first: const str = "Regex regex REGEX!"; const result = str. replace(pattern, "JS"); console. nrzvj bocdgf jncaiqgqp fakvy mwavdt quuycxov rxtt szdcdmc gmx dgcss dpz zomf zujsez zqkr imb