Substring

Extracts a portion of a string by position and optional length.

Signature

Substring(string text, number start, number length?)

Parameters

• text (string): The source string.
• start (number): The zero-based starting index (truncated to integer).
• length (number, optional): The number of characters to extract. If omitted, extracts to the end of the string.

Returns

• string: The extracted substring. Returns "" if no characters can be extracted.

Description

Extracts a substring with safe bounds handling:

• Negative start is clamped to 0.
• start beyond the string length returns "".
• length is clamped to the available characters remaining.
• length <= 0 returns "".
• If length is omitted, extracts from start to the end.

Examples

var a = Substring("Hello World", 0, 5)
# a = "Hello"

var b = Substring("Hello World", 6)
# b = "World"

# Safe bounds - start beyond length
var c = Substring("Hello", 10)
# c = ""

# Safe bounds - length exceeds string
var d = Substring("Hi", 0, 100)
# d = "Hi"

# Negative start clamped to 0
var e = Substring("Hello", -5, 3)
# e = "Hel"