not — GTM Variable Template for Value

VARIABLES › VALUE

not CORE Value

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

Negates a boolean value. Returns false for truthy values and true for falsy values.

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When to Use This

Conditional Logic

Branch logic based on conditions — if/else, ternary, boolean gates.

Type Conversion

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

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Examples

Negate true▶ Try

INPUT

Value to Negate: true

OUTPUT

false

Negate false▶ Try

INPUT

Value to Negate: false

OUTPUT

true

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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.

not

Read-Only Try Live

Value to Negate

💾 The boolean or truthy/falsy value to negate.

Supported formats:
  ✓ Boolean: true, false
  ✓ Any value: truthy/falsy values will be coerced to boolean

Input Setup

Input Function (optional)

⚙️ Optional pre-processing function applied to the value before negating (e.g., type conversion, normalization).

Result Handling

Output Function (optional)

⚙️ Optional function to apply to the negated boolean before returning it (e.g., val => val ? 'yes' : 'no', val => val.toString()). Useful for chaining transformations on the output.

Value to Negate 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.

not()

+ Chain another variable

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Related Variables

Same category: Value

→ NaN → apply → applyChain → emptyArray → emptyObject → emptyObjectArray → emptyString → false → falseTo → falsyTo → filterValue → getLength → getType → identity → mapTruthiness → null → nullTo → parseValue → regexTableLookupAll → regexTableLookupCallback → true → undefinedTo → zero

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Under the Hood

📜 View Implementation Code

/**
 * Negates a boolean value.
 *
 * @param {boolean} data.src - The boolean value to negate.
 * @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 negating.
 *
 * @returns {boolean} The negated boolean value.
 *
 * @framework ggLowCodeGTMKit
 */
const not = function(value) {
    return !value;
};
const safeFunction = fn => typeof fn === 'function' ? fn : x => x;
const out = safeFunction(data.out);
// ===============================================================================
// not - Direct mode
// ===============================================================================
const applyCast = (castFn, value) => safeFunction(castFn)(value);
const value = applyCast(data.pre, data.src);
return out(not(value));
// ===============================================================================
// not() – Apply Mode
// ===============================================================================
/*
return function(value) {
   return out(not(value));
};
*/

🧪 View Test Scenarios (3 tests)

✅ '[example] Negate true'
✅ '[example] Negate false'
✅ Test negating truthy value returns false