🧩 NOT — GTM Variable Template for Logic

VARIABLES › LOGIC

🧩 NOT CORE Logic

Direct (.tpl) Add to GTM

Checks the provided list of parameters and returns true if all values are falsy, false otherwise.

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When to Use This

Logic Operations

Boolean algebra — AND, OR, NOT, XOR for combining conditions.

Comparison

Test equality, containment, and ordering between values.

URL Processing

Parse, build, decode, and manipulate URLs and query parameters.

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Examples

All falsy returns true▶ Try

INPUT

Values To Test: [
{val: false},
{val: 0},
{val: ''},
{val: null},
{val: undefined}
]

OUTPUT

true

One truthy returns false▶ Try

INPUT

Values To Test: [
{val: false},
{val: 0},
{val: 'hello'},
{val: null}
]

OUTPUT

false

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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

NOT ⬇

Values To Test

⊖

Add Row

Input Setup

Input Function (optional)

Optional pre-processing function applied to each value 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 + ' €'`). Useful for chaining transformations on the output.

Values To Test list

✕

+ Add Row

🔗 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: Logic

→ isArray → isDefined → isEmpty → isEmptyString → isEqualTo → isFalsy → isFunction → isGreaterThan → isGreaterThanOrEqualTo → isInRange → isInfinity → isInteger → isJSON → isLessThan → isLessThanOrEqualTo → isNaN → isNotArray → isNotEmptyString → isNotFunction → isNotJSON → isNotNaN → isNotNull → isNotNumber → isNotObject → isNotString → isNotURL → isNull → isNumber → isObject → isPrimitive → isSHA256 → isString → isStringifiedNumber → isTruthy → isURL → isUndefined → isUnixTimestamp → isUnixTimestampMilliseconds → isUnixTimestampSeconds → isValidNumber → 🧩 AND → 🧩 IF (else) → 🧩 IF AND_OR → 🧩 IF ELSE IF (Advanced) → 🧩 IF ELSE IF (Predefined) → 🧩 OR → 🧩 XOR

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Under the Hood

📜 View Implementation Code

/**
 * Returns `false` as soon as a truthy value is found in the list.
 * Returns *`true`* only if **all values** are falsy.
 *
 * @param {Array<Object>} ls1 - List of parameter objects to evaluate.
 * @param {*} ls1[].val - Value to evaluate for truthiness
 *
 * @returns {boolean} `false` if any value is truthy, `true` if all are falsy.
 *
 * @framework ggLowCodeGTMKit
 */
const not = function(ls1) {
  for (const parameter of ls1) {
    if (!parameter) {
      continue;
    }
    if (!!parameter.val) {
      return false;
    }
  }
  return true;
};
const safeFunction = fn => typeof fn === 'function' ? fn : x => x;
const applyCast = (castFn, value) => safeFunction(castFn)(value);
const out = safeFunction(data.out);
// ===============================================================================
// not - Direct mode
// ===============================================================================
const values = (data.ls1 || []).map(item => item ? {val: applyCast(data.pre, item.val)} : item);
return out(not(values));

🧪 View Test Scenarios (6 tests)

✅ '[example] All falsy returns true'
✅ '[example] One truthy returns false'
✅ Test first value truthy returns false immediately
✅ Test empty list returns true
✅ Test with null/undefined items skipped
✅ Test with pre function that transforms values