Replace all without worrying about capitalization

Question

Replace all without worrying about capitalization

Does anyone have a solution for a case-insensitive replacing function in JavaScript? For instance, if I want to replace 'is' with 'as', it should work similar to this:

'This iS IIS'.replaceAll('is', 'as');

The expected result would be:

'Thas as Ias'

Any suggestions on how to achieve this?

UPDATE:

I would like to be able to use a variable in the replacement process. For example:

var searchStr = 'is';
'This iS IIS'.replaceAll(searchStr, 'as');

javascript

Answer 1

Answer №1

Give regex a shot:

'Try using regular expressions'.replace(/using/ig, 'with');

Example in action: http://jsfiddle.net/6xBwt/

For instance:
Utilizing RegExp object:

var searchMask = "using";
var regEx = new RegExp(searchMask, "ig");
var replaceMask = "with";

var result = 'Try using regular expressions'.replace(regEx, replaceMask);

console.log(result);

Answer 2

Give regex a shot:

'Try using regular expressions'.replace(/using/ig, 'with');

Example in action: http://jsfiddle.net/6xBwt/

For instance:
Utilizing RegExp object:

var searchMask = "using";
var regEx = new RegExp(searchMask, "ig");
var replaceMask = "with";

var result = 'Try using regular expressions'.replace(regEx, replaceMask);

console.log(result);

Answer 3

Answer №2

String.prototype.replaceAll = function(strFind, strReplace) {
    // Implementation inspired by http://stackoverflow.com/a/3561711/556609
    var escapedStr = strFind.replace(/[-\/\\^$*+?.()|[\]{}]/g, '\\$&');
    var regex = new RegExp(escapedStr, 'ig');
    return this.replace(regex, strReplace);
};

This code snippet replicates the example you provided.

'This iS IIS'.replaceAll('is', 'as');

Output:

'Thas as Ias'

Answer 4

String.prototype.replaceAll = function(strFind, strReplace) {
    // Implementation inspired by http://stackoverflow.com/a/3561711/556609
    var escapedStr = strFind.replace(/[-\/\\^$*+?.()|[\]{}]/g, '\\$&');
    var regex = new RegExp(escapedStr, 'ig');
    return this.replace(regex, strReplace);
};

This code snippet replicates the example you provided.

'This iS IIS'.replaceAll('is', 'as');

Output:

'Thas as Ias'

Answer 5

Answer №3

When utilizing the regex solution, potential issues may arise if your replacement string contains characters like "?". To avoid this, you can either escape all regex characters or implement the following workaround:

String.replacei = String.prototype.replacei = function (rep, rby) {
    var pos = this.toLowerCase().indexOf(rep.toLowerCase());
    return pos == -1 ? this : this.substr(0, pos) + rby + this.substr(pos + rep.length);
};

The above approach does not replace all instances of 'is' in the string. To address this, a while loop can be included within the function.

Answer 6

When utilizing the regex solution, potential issues may arise if your replacement string contains characters like "?". To avoid this, you can either escape all regex characters or implement the following workaround:

String.replacei = String.prototype.replacei = function (rep, rby) {
    var pos = this.toLowerCase().indexOf(rep.toLowerCase());
    return pos == -1 ? this : this.substr(0, pos) + rby + this.substr(pos + rep.length);
};

The above approach does not replace all instances of 'is' in the string. To address this, a while loop can be included within the function.

Answer 7

Answer №4

This section showcases the difference between using Regex and Non-regex in Paul's response.

The regex code used for comparison can be attributed to Benjamin Fleming's answer."

JSPerf
Case-sensitive
Regex: 66,542 Operations/sec
Non-Regex: 178,636 Operations/sec (split - join)

Incase-sensitive
Regex: 37,837 Operations/sec
Non-Regex: 12,566 Operations/sec (indexOf - substr)

String.prototype.replaces = function(str, replace, incaseSensitive) {
    if(!incaseSensitive){
        return this.split(str).join(replace);
    } else { 
        // Replace this part with regex for more performance

        var strLower = this.toLowerCase();
        var findLower = String(str).toLowerCase();
        var strTemp = this.toString();

        var pos = strLower.length;
        while((pos = strLower.lastIndexOf(findLower, pos)) != -1){
            strTemp = strTemp.substr(0, pos) + replace + strTemp.substr(pos + findLower.length);
            pos--;
        }
        return strTemp;
    }
};

// Example
var text = "A Quick Dog Jumps Over The Lazy Dog";
console.log(text.replaces("dog", "Cat", true));

Answer 8

This section showcases the difference between using Regex and Non-regex in Paul's response.

The regex code used for comparison can be attributed to Benjamin Fleming's answer."

JSPerf
Case-sensitive
Regex: 66,542 Operations/sec
Non-Regex: 178,636 Operations/sec (split - join)

Incase-sensitive
Regex: 37,837 Operations/sec
Non-Regex: 12,566 Operations/sec (indexOf - substr)

String.prototype.replaces = function(str, replace, incaseSensitive) {
    if(!incaseSensitive){
        return this.split(str).join(replace);
    } else { 
        // Replace this part with regex for more performance

        var strLower = this.toLowerCase();
        var findLower = String(str).toLowerCase();
        var strTemp = this.toString();

        var pos = strLower.length;
        while((pos = strLower.lastIndexOf(findLower, pos)) != -1){
            strTemp = strTemp.substr(0, pos) + replace + strTemp.substr(pos + findLower.length);
            pos--;
        }
        return strTemp;
    }
};

// Example
var text = "A Quick Dog Jumps Over The Lazy Dog";
console.log(text.replaces("dog", "Cat", true));

Answer 9

Answer №5

Please take note that there is an issue with a previous answer provided. If your initial string begins with the replacement word, you may end up stuck in an endless loop.

String.prototype.replaces = function(str, replace, incaseSensitive) {
    if(!incaseSensitive){
        return this.split(str).join(replace);
    } else { 
        // Implement regex here for better performance

        var strLower = this.toLowerCase();
        var findLower = String(str).toLowerCase();
        var strTemp = this.toString();

        var pos = strLower.length;
        while((pos = strLower.lastIndexOf(findLower, pos)) != -1){
            strTemp = strTemp.substr(0, pos) + replace + strTemp.substr(pos + findLower.length);
            if (pos == 0) break; // Resolves the bug
            pos--;
        }
        return strTemp;
    }
};

// Example usage
var text = "Dog Jumps Over The Lazy Dog";
console.log(text.replaces("dog", "Cat", true));

Answer 10

Please take note that there is an issue with a previous answer provided. If your initial string begins with the replacement word, you may end up stuck in an endless loop.

String.prototype.replaces = function(str, replace, incaseSensitive) {
    if(!incaseSensitive){
        return this.split(str).join(replace);
    } else { 
        // Implement regex here for better performance

        var strLower = this.toLowerCase();
        var findLower = String(str).toLowerCase();
        var strTemp = this.toString();

        var pos = strLower.length;
        while((pos = strLower.lastIndexOf(findLower, pos)) != -1){
            strTemp = strTemp.substr(0, pos) + replace + strTemp.substr(pos + findLower.length);
            if (pos == 0) break; // Resolves the bug
            pos--;
        }
        return strTemp;
    }
};

// Example usage
var text = "Dog Jumps Over The Lazy Dog";
console.log(text.replaces("dog", "Cat", true));

Answer 11

Answer №6

Employ a regex pattern.

'Change the text'.replace(/pattern/ig, 'replacement')

Answer 12

Employ a regex pattern.

'Change the text'.replace(/pattern/ig, 'replacement')

Answer 13

Answer №7

If you're concerned about the performance impact of regular expressions and want an alternative solution, one option is to create a personalized function. This function can iterate through the given string, identify matches regardless of their case sensitivity, and then apply replacements accordingly. It's worth noting that although this custom approach can be effective in some cases, it may not always outperform using a proficiently designed regular expression - especially when dealing with lengthy strings or intricate replacement patterns.

function replaceCaseInsensitive(str, find, replace) {
    let result = "";
    let findLower = find.toLowerCase();
    let index = 0;

    while (index < str.length) {
        if (str.substring(index).toLowerCase().startsWith(findLower)) {
            result += replace;
            index += find.length;
        } else {
            result += str[index];
            index++;
        }
    }

    return result;
}

// Example scenario
let originalString = "Greetings Earthlings";
let newString = replaceCaseInsensitive(originalString, "earthlings", "Martians");
console.log(newString); // Output: Greetings Martians

Answer 14

If you're concerned about the performance impact of regular expressions and want an alternative solution, one option is to create a personalized function. This function can iterate through the given string, identify matches regardless of their case sensitivity, and then apply replacements accordingly. It's worth noting that although this custom approach can be effective in some cases, it may not always outperform using a proficiently designed regular expression - especially when dealing with lengthy strings or intricate replacement patterns.

function replaceCaseInsensitive(str, find, replace) {
    let result = "";
    let findLower = find.toLowerCase();
    let index = 0;

    while (index < str.length) {
        if (str.substring(index).toLowerCase().startsWith(findLower)) {
            result += replace;
            index += find.length;
        } else {
            result += str[index];
            index++;
        }
    }

    return result;
}

// Example scenario
let originalString = "Greetings Earthlings";
let newString = replaceCaseInsensitive(originalString, "earthlings", "Martians");
console.log(newString); // Output: Greetings Martians

Answer 15

Answer №8

Insensitivity in Replacement: 12,053,033 replacements made in 1 second
for the operation ReplaceAll("Dog Jumps Over The Lazy Dog", "dog", "Cat")

Here is an example:

function ReplaceAll(base,told,tnew) { // insensitive replacement
  if (told=="") {return base;}
  var u=base.toLowerCase();
  var t=told.toLowerCase();
  var ss=""; var p=-1; var i=0;
  p=u.indexOf(t);
  if (p>-1) {
    let mLen=told.length;
    while (p>=0) {
      ss+=base.substr(0,p)+tnew;
      i=p+mLen;
      base=base.substr(i);
      u=u.substr(i);
      p=u.indexOf(t);
    }
    ss+=base; //fix bug
    return ss;
  }
  return base;
}    
/*Test:
    
    function loopThrough() {
             for (let i = 0; i < 60000000; i++) {
               let s=ReplaceAll("Dog Jumps Over The Lazy Dog","dog","Cat");
             }
          }
    
    $(document).ready(function(){
      $("button").click(function(){
          //alert(ReplaceAll("Dog Jumps Over The Lazy Dog","dog", "Cat"));
          
          document.getElementById("demo").innerHTML = '...';
          let startTime = new Date();
          loopThrough();
          let endTime = new Date();
          let timeElapsed = endTime - startTime;
          document.getElementById("demo").innerHTML =  "elapsed times: " + timeElapsed + " milliseconds.";
*/

Answer 16

Insensitivity in Replacement: 12,053,033 replacements made in 1 second
for the operation ReplaceAll("Dog Jumps Over The Lazy Dog", "dog", "Cat")

Here is an example:

function ReplaceAll(base,told,tnew) { // insensitive replacement
  if (told=="") {return base;}
  var u=base.toLowerCase();
  var t=told.toLowerCase();
  var ss=""; var p=-1; var i=0;
  p=u.indexOf(t);
  if (p>-1) {
    let mLen=told.length;
    while (p>=0) {
      ss+=base.substr(0,p)+tnew;
      i=p+mLen;
      base=base.substr(i);
      u=u.substr(i);
      p=u.indexOf(t);
    }
    ss+=base; //fix bug
    return ss;
  }
  return base;
}    
/*Test:
    
    function loopThrough() {
             for (let i = 0; i < 60000000; i++) {
               let s=ReplaceAll("Dog Jumps Over The Lazy Dog","dog","Cat");
             }
          }
    
    $(document).ready(function(){
      $("button").click(function(){
          //alert(ReplaceAll("Dog Jumps Over The Lazy Dog","dog", "Cat"));
          
          document.getElementById("demo").innerHTML = '...';
          let startTime = new Date();
          loopThrough();
          let endTime = new Date();
          let timeElapsed = endTime - startTime;
          document.getElementById("demo").innerHTML =  "elapsed times: " + timeElapsed + " milliseconds.";
*/

Answer 17

Answer №9

If you are looking to replace strings, consider using the str_ireplace function from php.js as it even has the capability to replace strings within arrays.

Answer 18

If you are looking to replace strings, consider using the str_ireplace function from php.js as it even has the capability to replace strings within arrays.

Replace all without worrying about capitalization

Answer №1

Answer №2

Answer №3

Answer №4

Answer №5

Answer №6

Answer №7

Answer №8

Answer №9

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