Short Circuiting In JS

Short Circuiting In JS: Hello everyone, welcome to the nkcoderz.com website. In this article we will going to discuss about the Short Circuiting In JavaScript.

Table of Contents

Short-circuiting is a feature of JavaScript that allows you to stop the evaluation of an expression or a function call as soon as the result is known. This is done by using logical operators such as && (AND) and || (OR) in a way that makes use of their specific behavior.

The AND (&&) operator returns the first operand if it is falsy, otherwise it returns the second operand.

Code For AND (&&) operator In JavaScript

console.log(null && "hello");
console.log("hello" && "world");

Output

null

“world”

The OR (||) operator returns the first operand if it is truthy, otherwise it returns the second operand.

Code For OR (||) Operator In JavaScript

console.log(null || "hello");
console.log("hello" || "world");

Output

“hello”

“hello”

Short-circuiting can be used to assign a default value to a variable if it is undefined or null.

let x;
let y = x || "default value";
console.log(y);

Output

“default value”

This can also be useful to avoid making unnecessary function calls or calculations.

function getData() {
  if (!data) {
    return null;
  }
  // do something with data
}

let data = getData() || "default data";

In this example, the function call getData() is only executed if the variable data is not truthy, allowing you to avoid unnecessary function calls.

Conclusion

Short-circuiting behavior of these operators allow us to write more efficient and compact code and also helps in avoiding unnecessary computations.