replaceAllWithRegex — GTM Variable Template for String

replaceAllWithRegex CORE String

Replaces all occurrences of a regular expression pattern in a string with a replacement value. Useful for pattern-based text transformations and data cleaning.

When to Use This

String Manipulation

Transform, clean, and normalize text data for consistent downstream processing.

Type Conversion

Safely convert between data types — strings, numbers, booleans, arrays, objects.

Filtering

Select or exclude items from collections based on criteria or predicates.

Formatting

Normalize casing, spacing, encoding, and presentation of data values.

Examples

Mask all numbers

INPUT

Input String: Order 123 and Order 456
Regular Expression Pattern: \\d+
Replacement Value: XXX

OUTPUT

Order XXX and Order XXX

Normalize whitespace

INPUT

Input String: hello world test
Regular Expression Pattern: \\s+
Replacement Value:

OUTPUT

hello world test

GTM Configuration

This is what you'll see when you open this variable in Google Tag Manager. Hover the icons for details.

replaceAllWithRegex

Input String

Regular Expression Pattern

🔍 The regular expression pattern to search for in the string. All occurrences will be replaced.

Supported formats:
✓ String (regex pattern)

⚠️ Escaping note: In this UI field, use single backslash (e.g., d+ for digits). GTM automatically handles the escaping.

Replacement Value

Input Setup

Input Function (optional)

Result Handling

Output Function (optional)

⚙️ Optional function to apply to the result string before returning it (e.g., str => str.trim(), str => str.toUpperCase()). Useful for chaining transformations on the output.

Input String string

💡 Type any text to see the result update live

🎯 Using special value — click input to type instead

Test with:

Falsy

Truthy

Regular Expression Pattern string

Replacement Value string

🔗 Result Handling — Chain Variables

replaceAllWithRegex()

Under the Hood

📜 View Implementation Code

/**
 * Replaces all occurrences of a regular expression pattern in a string with a replacement value.
 * 
 * @param {string} data.src - The input string where replacement will occur.
 * @param {string} data.ptn - The regular expression pattern to search for in the string.
 * @param {string} data.rep - The replacement value to use.
 * @param {Function|string} [data.out] - Optional output handler: function to transform result or string with format.
 *
 * Direct-mode specific parameters:
 * @param {Function} [data.pre] - Optional pre-processor function to transform src before replacement.
 * 
 * @returns {string} The string with all occurrences of the regex pattern replaced.
 *
 * @framework ggLowCodeGTMKit
 */
const matchAll = function(stringToMatch, regexPattern) {
  const matches = [];
  let index = 0;
  while (index < stringToMatch.length) {
    const match = stringToMatch.substring(index).match(regexPattern);
    if (match) {
      matches.push(match[0]);
      index += match.index + match[0].length;
    } else {
      break;
    }
  }
  return matches.length > 0 ? matches : null;
};

const replaceAllWithRegex = function(input, pattern, replacement) {
    if (typeof input !== 'string' || typeof pattern !== 'string' || typeof replacement !== 'string') {
        return input;
    }
    
    const matches = matchAll(input, pattern);
    
    if (matches === null) {
        return input; // No matches found
    }
    
    let result = input;
  
    for (let i = 0; i < matches.length; i++) {
        result = result.replace(matches[i], replacement);
    }
    
    return result;
};

const safeFunction = fn => typeof fn === 'function' ? fn : x => x;
const out = safeFunction(data.out);
// ===============================================================================
// replaceAllWithRegex - Direct mode
// ===============================================================================
const applyCast = (castFn, value) => safeFunction(castFn)(value);
const processedInput = applyCast(data.pre, data.src);
return out(replaceAllWithRegex(processedInput, data.ptn, data.rep));
// ===============================================================================
// replaceAllWithRegex(...) – Apply Mode
// ===============================================================================
/*
return function(input, pattern, replacement) {
   return out(replaceAllWithRegex(input, data.ptn, data.rep));
};
*/

🧪 View Test Scenarios (14 tests)

✅ Test with non-string input returns original value
✅ '[example] Mask all numbers'
✅ Test removing dollar signs
✅ '[example] Normalize whitespace'
✅ Test replacing word characters
✅ Test with no matches returns original string
✅ Test replacing special characters with escape sequences
✅ Test replacing emails with placeholder
✅ Test with non-string pattern returns original string
✅ Test with non-string replacement returns original string
✅ Test replacing line breaks
✅ Test case-insensitive pattern
✅ Test with null string returns original value
✅ Test with undefined string returns original value

replaceAllWithRegex — GTM Variable Template for String

When to Use This

Examples

GTM Configuration

Related Variables

Under the Hood