Definition

string substring(string $text, integer $startIndex, int $substringLength)

Returns the substring of $text starting at $startIndex with length $substringLength.

Parameters

string $text

Text to search select a substring of.

number $startIndex

The index of the original string where the first character of the substring is. Starts from zero.

int $substringlength

The length of the substring to be returned.

Returns

Substring of $text starting at $startIndex of length $substringLength.

Examples

{
  a: substring('Hello, world!', `7`, `5`),
  b: substring('Hello, world!', `7`, `50`),
  c: substring('Hello, world!', `-7`, `5`),      // Error
  d: substring('Hello, world!', `0`, `0`),
  e: substring('Hello, world!', `0`, `true`),
  f: substring('Hello, world!', `0`, `null`),    // Error
  g: substring('', `0`, `10`),
  h: substring('', `1`, `10`),
  i: substring(`null`, `0`, `1`)
}

{
  "a": "world",
  "b": "world!",
  "d": "",
  "e": "H",
  "g": "",
  "h": "",
  "i": null
}