@rbxts/jsnatives


isInteger

Determines whether the passed value is an integer.

Signature

function isInteger(value: number): boolean

Description

The Number.isInteger() method determines whether the passed value is an integer - that is, it checks if the type of the value is Number and the value has no decimal part.

Parameters

Return value

Examples

Basic Usage

// Integer numbers
Number.isInteger(42);           // true
Number.isInteger(-42);          // true
Number.isInteger(0);            // true
Number.isInteger(42.0);         // true (42.0 is the same as 42)


// Non-integer numbers
Number.isInteger(42.5);         // false
Number.isInteger(0.1);          // false

Validating Integer Input

// Validate that a value can be used as an array index
function isValidIndex(value: unknown): boolean {
  // Check if it's an integer and non-negative
  return Number.isInteger(value) && (value as number) >= 0;
}


// Usage
isValidIndex(42);          // true
isValidIndex(-1);          // false (negative)
isValidIndex(3.5);         // false (not an integer)
isValidIndex("5");         // false (not a number)