toSnakeCase — GTM Variable Template for String

VARIABLES › STRING

toSnakeCase CORE String

Direct (.tpl) Apply (.tpl) Add to GTM

Converts a string to snake_case format. Returns undefined if the input is not a valid string.

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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.

Formatting

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

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Examples

Spaces to snake_case▶ Try

INPUT

String To Convert: hello world test

OUTPUT

hello_world_test

Hyphens to snake_case▶ Try

INPUT

String To Convert: hello-world-test

OUTPUT

hello_world_test

Non-string input returns undefined▶ Try

INPUT

String To Convert: 12345

OUTPUT

undefined

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Live Sandbox

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toSnakeCase

Read-Only Try Live

String To Convert

💾 The string to convert to snake_case format.

Supported formats:
  ✓ String

Input Setup

Input Function (optional)

⚙️ Optional pre-processing function applied to the input before internal logic (e.g., normalize case, clean string). Internal transformations such as snake_case conversion will still apply afterward.

Result Handling

Output Function (optional)

⚙️ Optional function to apply to the result before returning it (e.g., str => str + '_suffix', val => val.replace(/^_/, '') to remove leading underscores). Useful for chaining transformations on the output.

String To Convert string

💡 Type any text to see the result update live

🎯 Using special value — click input to type instead

Test with:

Falsy undefined null "" empty 0 false NaN

Truthy true 42 "hello" {} empty [] empty {a:1} [1,2,3]

🔗 Result Handling — Chain Variables

Chain apply-mode variables to the output. Each variable receives the result of the previous one.

toSnakeCase()

+ Chain another variable

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Related Variables

Same category: String

→ charAt → collapseWhitespace → concat → countWordsInString → endsWith → extract → extractFirstSegment → extractNumber → fromBase64 → indexOf → left → matchAll → matchRegex → normalizeEmail → normalizePhone → padEnd → padStart → parseJSON → replaceAll → replaceAllWithRegex → replaceFirst → right → safeSplit → search → slice → slugify → split → startsWith → stripAccents → stripHtml → substringAfter → substringBefore → test → toBase64 → toCamelCase → toJsonString → toKebabCase → toLocaleLowerCase → toLocaleUpperCase → toLowerCase → toNumber → toStartCase → toString → toStringRepresentation → toUpperCase → toUpperFirst → trim → trimEnd → trimStart → truncate

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Under the Hood

📜 View Implementation Code

/**
* Converts a string to snake_case format.
*
* @param {string} data.src - The string to convert to snake_case.
* @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 conversion.
*
* @returns {string|undefined} The string in snake_case format, or undefined if the input is not a valid string.
*
* @framework ggLowCodeGTMKit
*/
const toSnakeCase = function(string) {
   if (typeof string === 'string') {
       const pattern = "[_\\s-]+";
       const replacement = '_';

       const replaceAllWithRegex = function(input, pattern, replacement) {
           if (typeof input !== 'string' || typeof pattern !== 'string' || typeof replacement !== 'string') {
               return input;
           }
           let result = input;
           let lastIndex = 0;

           while (lastIndex < result.length) {
               const remainingStr = result.substring(lastIndex);
               const matchObj = remainingStr.match(pattern);
               if (matchObj === null) {
                   break;
               }

               const actualMatchIndex = lastIndex + (matchObj.index || 0);

               result = result.substring(0, actualMatchIndex) +
                        replacement +
                        result.substring(actualMatchIndex + matchObj[0].length);
               lastIndex = actualMatchIndex + replacement.length;
           }
           return result;
       };


       let result = replaceAllWithRegex(string, pattern, replacement);

       result = result.toLowerCase();
       return result;
   }
   return undefined;
};
const safeFunction = fn => typeof fn === 'function' ? fn : x => x;
const out = safeFunction(data.out);
// ===============================================================================
// toSnakeCase - Direct mode
// ===============================================================================
const applyCast = (castFn, value) => safeFunction(castFn)(value);
const value = applyCast(data.pre, data.src);
return out(toSnakeCase(value));
// ===============================================================================
// toSnakeCase() – Apply Mode
// ===============================================================================
/*
return function(value) {
  return out(toSnakeCase(value));
};
*/

🧪 View Test Scenarios (5 tests)

✅ '[example] Spaces to snake_case'
✅ '[example] Hyphens to snake_case'
✅ Mixed case string with multiple separators - should convert to snake_case
✅ Already in snake_case - should remain unchanged
✅ '[example] Non-string input returns undefined'