slice — GTM Variable Template for String

VARIABLES › STRING

slice EXTENDED String

Direct (.tpl) Apply (.tpl)

Extract and return a portion of a string or array starting from the provided starting index and optional ending index.

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Examples

Extract substring▶ Try

INPUT

Data To Slice: Hello World
Start Index: 0
End Index: 5

OUTPUT

Hello

Negative index slices from end▶ Try

INPUT

Data To Slice: abcdef
Start Index: -3
End Index: undefined

OUTPUT

def

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GTM Configuration

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slice

Read-Only Try Live

Data To Slice

💾 The string or array to slice.

Supported formats:
  ✓ String
  ✓ Array

Start Index

▶️ The starting index where to begin the slice.

Supported formats:
  ✓ Number
  ✓ String

End Index

⏹️ The index where to end the slice (optional, defaults to the end of the string/array).

Supported formats:
  ✓ Number
  ✓ String

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.

Data To Slice 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]

Start Index number

End Index number

🔗 Result Handling — Chain Variables

Chain apply-mode variables to the output. Each variable receives the result of the previous one.

slice()

+ Chain another variable

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Related Variables

Same category: String

→ assignParamsToString → charAt → concatenateValues → countWordsInString → endsWith → extract → extractFirstSegment → extractNumber → fromBase64 → indexOf → left → matchAll → matchRegex → omitParamsFromString → padEnd → padStart → pickParamsFromString → replaceAll → replaceAllWithRegex → replaceFirst → right → safeSplit → sanitizeTextAndRemoveHtml → sanitizeTextLite → search → split → startsWith → test → toBase64 → toCamelCase → toJsonString → toKebabCase → toLocaleLowerCase → toLocaleUpperCase → toLowerCase → toNumber → toSnakeCase → toStartCase → toString → toStringRepresentation → toUpperCase → toUpperFirst → trim → trimEnd → trimStart → truncate

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Under the Hood

📜 View Implementation Code

/**
* Extract and return a portion of a string or array starting from the provided starting index and optional ending index.
* 
* @param {string|Array} data.src - The string or array to slice.
* @param {number|string} data.sta - The starting index where to begin the slice.
* @param {number|string} data.end - The index where to end the slice (optional, defaults to the end of the string/array).
* @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 slicing.
* 
* @returns {any} Returns a string or array containing the sliced portion, or undefined if input is invalid.
*
* @framework ggLowCodeGTMKit
*/
const getType = require('getType');
const makeNumber = require('makeNumber');

const slice = function(searchData, start, end) {
   const startNum = makeNumber(start);
   if (searchData == null || startNum !== startNum) { return undefined; }
   if (!(getType(searchData) === 'array' || getType(searchData) === 'string')) { 
       return undefined;
   }
   const endNum = end === undefined ? searchData.length : makeNumber(end);
   return searchData.slice(startNum, endNum);
};
const safeFunction = fn => typeof fn === 'function' ? fn : x => x;
const out = safeFunction(data.out);
// ===============================================================================
// slice - Direct mode
// ===============================================================================
const applyCast = (castFn, value) => safeFunction(castFn)(value);
const value = applyCast(data.pre, data.src);
return out(slice(value, data.sta, data.end));
// ===============================================================================
// slice(...) – Apply Mode
// ===============================================================================
/*
return function(value, start, end) {
   start = data.rp1 ? data.sta : start;
   end = data.rp2 ? data.end : end;
   return out(slice(value, start, end));
};
*/

🧪 View Test Scenarios (5 tests)

✅ '[example] Extract substring'
✅ Array slice with start and end - returns subarray
✅ String slice with only start - slices to end
✅ '[example] Negative index slices from end'
✅ Invalid input - returns undefined