toNumber — GTM Variable Template for String

VARIABLES › STRING

toNumber CORE String

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

Converts the input into a number, or returns NaN if the input cannot be converted.

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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.

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Examples

String to number▶ Try

INPUT

Value To Convert: 42

OUTPUT

42

Decimal string to number▶ Try

INPUT

Value To Convert: 3.14

OUTPUT

3.14

Non-numeric returns NaN▶ Try

INPUT

Value To Convert: hello

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.

toNumber

Read-Only Try Live

Value To Convert

💾 The value to be converted into a number.

Supported formats:
  ✓ Any

Input Setup

Input Function (optional)

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

Result Handling

Output Function (optional)

⚙️ Optional function to apply to the result before returning it (e.g., str => str + ' €', val => val !== undefined for boolean conversion). Useful for chaining transformations on the output.

Value To Convert any

💡 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.

toNumber()

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

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Under the Hood

📜 View Implementation Code

/**
* Converts the input into a number.
*
* @param {any} data.src - The value to be converted into a number.
* @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 {number} The converted number, or NaN if the input cannot be converted.
*
* @framework ggLowCodeGTMKit
*/
const makeNumber = require('makeNumber');

const toNumber = function(input) {
   return makeNumber(input);
};

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

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

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

🧪 View Test Scenarios (5 tests)

✅ '[example] String to number'
✅ '[example] Decimal string to number'
✅ Already a number - should return unchanged
✅ Boolean true - should convert to 1
✅ '[example] Non-numeric returns NaN'