trim — GTM Variable Template for String

VARIABLES › STRING

trim CORE String

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

Trims any leading or trailing whitespace from a valid string. Returns an empty string when 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.

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Examples

Trim leading and trailing spaces▶ Try

INPUT

String To Trim: hello world

OUTPUT

hello world

Only spaces returns empty string▶ Try

INPUT

String To Trim:

OUTPUT

""

Non-string returns empty string▶ Try

INPUT

String To Trim: 123

OUTPUT

""

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Live Sandbox

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

trim

Read-Only Try Live

String To Trim

💾 The value to be converted to a string and trimmed.

Supported formats:
  ✓ String

Input Setup

Input Function (optional)

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

Result Handling

Output Function (optional)

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

String To Trim 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.

trim()

+ 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 → toSnakeCase → toStartCase → toString → toStringRepresentation → toUpperCase → toUpperFirst → trimEnd → trimStart → truncate

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Under the Hood

📜 View Implementation Code

/**
* Trims whitespace from both ends of a string.
*
* @param {any} data.src - The value to be converted to a string.
* @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 trimming.
*
* @returns {string} The string representation of the input with whitespace trimmed, or an empty string.
*
* @framework ggLowCodeGTMKit
*/
const trim = function(string) {
   return typeof string === 'string' ? string.trim() : "";
};

const safeFunction = fn => typeof fn === 'function' ? fn : x => x;
const out = safeFunction(data.out);

// ===============================================================================
// trim - Direct mode
// ===============================================================================
const applyCast = (castFn, value) => safeFunction(castFn)(value);
const value = applyCast(data.pre, data.src);
return out(trim(value));

// ===============================================================================
// trim() – Apply Mode
// ===============================================================================
/*
return function(value) {
  return out(trim(value));
};
*/

🧪 View Test Scenarios (9 tests)

✅ Trim both ends
✅ String with only leading spaces - should trim start
✅ String with only trailing spaces - should trim end
✅ String with no whitespace - should return same string
✅ '[example] Trim leading and trailing spaces'
✅ '[example] Only spaces returns empty string'
✅ Trim tabs and newlines
✅ '[example] Non-string returns empty string'
✅ Non-string input (null) - should return empty string