@rbxts/jsnatives


isSafeInteger

Determines whether the passed value is a safe integer.

Signature

function isSafeInteger(value: number): boolean

Description

The Number.isSafeInteger() method determines whether the provided value is a number that is a safe integer. A safe integer is an integer that can be exactly represented as an IEEE-754 double precision number, which means it must be between -(2^53 - 1) and 2^53 - 1 inclusive.

Parameters

Return value

Examples

Basic Usage

// Safe integers
Number.isSafeInteger(42);                     // true
Number.isSafeInteger(-42);                    // true
Number.isSafeInteger(0);                      // true
Number.isSafeInteger(9007199254740991);       // true (MAX_SAFE_INTEGER)
Number.isSafeInteger(-9007199254740991);      // true (MIN_SAFE_INTEGER)


// Unsafe integers (outside safe range)
Number.isSafeInteger(9007199254740992);       // false (MAX_SAFE_INTEGER + 1)
Number.isSafeInteger(-9007199254740992);      // false (MIN_SAFE_INTEGER - 1)


// Non-integers
Number.isSafeInteger(3.14);                   // false
Number.isSafeInteger(NaN);                    // false
Number.isSafeInteger(Infinity);               // false
Number.isSafeInteger(-Infinity);              // false


// Non-numbers
Number.isSafeInteger("42");                   // false
Number.isSafeInteger(null);                   // false

Checking for Safe Arithmetic

// Check if a calculation will produce a safe integer result
function safeAdd(a: number, b: number): number {
  const result = a + b;


  if (!Number.isSafeInteger(result)) {
    console.warn("Result exceeds safe integer limits and may lose precision");
  }


  return result;
}


// Usage
safeAdd(42, 100);                         // 142, no warning
safeAdd(Number.MAX_SAFE_INTEGER, 1);      // Warning about exceeding limits