getLength — GTM Variable Template for Value

VARIABLES › VALUE

getLength EXTENDED Value

Direct (.tpl) Apply (.tpl)

Returns the length of a string or array.

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Examples

String length▶ Try

INPUT

Value To Measure: hello world

OUTPUT

11

Array length▶ Try

INPUT

Value To Measure: [1, 2, 3, 4, 5]

OUTPUT

5

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GTM Configuration

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getLength

Read-Only Try Live

Value To Measure

💾 The value whose length is to be determined.

Supported formats:
  ✓ String
  ✓ Array
  ✓ Any (returns 0)

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 Measure array

💡 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.

getLength()

+ Chain another variable

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Related Variables

Same category: Value

→ NaN → apply → applyChain → emptyArray → emptyObject → emptyObjectArray → emptyString → false → falseTo → falsyTo → filterValue → getType → identity → mapTruthiness → not → null → nullTo → parseValue → regexTableLookupAll → regexTableLookupCallback → true → undefinedTo → zero

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Under the Hood

📜 View Implementation Code

/**
* Returns the length of a value, handling different types.
* 
* @param {any} data.src - The value whose length is to be determined.
* @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 getting length.
* 
* @returns {number} The length of the value if it's a string or array, 0 otherwise.
*
* @framework ggLowCodeGTMKit
*/
const getType = require('getType');
const getLength = function(value) {
   if (typeof value === 'string') { return value.length; }
   if (getType(value) === 'array') { return value.length; }
   return 0;
};
const safeFunction = fn => typeof fn === 'function' ? fn : x => x;
const out = safeFunction(data.out);
// ===============================================================================
// getLength - Direct mode
// ===============================================================================
const applyCast = (castFn, value) => safeFunction(castFn)(value);
const value = applyCast(data.pre, data.src);
return out(getLength(value));
// ===============================================================================
// getLength() – Apply Mode
// ===============================================================================
/*
return function(value) {
  return out(getLength(value));
};
*/

🧪 View Test Scenarios (7 tests)

✅ '[example] String length'
✅ Empty string - should return 0
✅ '[example] Array length'
✅ Empty array - should return 0
✅ Array with mixed types - should return array length
✅ Number input - should return 0
✅ Object returns 0