Question 15

Question

Can you explain how JavaScript handles big integers internally?

Answer

Here's a breakdown of how JavaScript manages large integers:

1. IEEE-754 Standard: JavaScript uses the IEEE-754 standard for representing floating-point numbers (which includes decimals). This standard works well for most everyday calculations, but it has limitations when dealing with very large whole numbers.

2. JavaScript's Number Type: By default, Number in JavaScript only supports a finite precision. The exact number of bits used varies depending on the environment, but it's limited enough that extremely large integers will result in rounding errors or overflow.

3. BigInts to the Rescue!

   • Introduced in ECMAScript 2020 (ES2020), BigInt provides a way to work with arbitrarily large whole numbers without these limitations.

   • Notation: You create a BigInt by appending an "n" after the number, e.g., 12345678901234567890n.

   const hugeNumber = 12345678901234567890n;
   console.log(hugeNumber); // Outputs the BigInt directly

   • Arithmetic: You can perform standard arithmetic operations (+, -, *, /) with BigInts, ensuring accurate results for truly massive calculations.

   const evenHuger = hugeNumber * 2n;
   console.log(evenHuger); //  Outputs the result of the BigInt multiplication

Key Points to Remember:

• Standard Number values in JavaScript have a limited precision, unsuitable for very large integers.

• Use BigInt when you need to work with arbitrarily large whole numbers without rounding errors or overflow.