JavaScript Code Blocks Explained with Examples

Introduction

In computer programming, a block or code block is a section of code which is grouped together. Blocks consist of one or more declarations and statements. A programming language that permits the creation of blocks, including blocks nested within other blocks, is called a block-structured programming language. JavaScript is one such programming language.

A block statement in JavaScript is used to group zero or more statements. The block is delimited by a pair of curly brackets.

{
  statement_1;
  statement_2;
  ...
  statement_n;
}

Examples

The block statement is commonly used with control flow statements (e.g. if...else , for , while ) and functions.

while (x < 10) {
  x++;
}

function addNums(num1, num2) {
  let sum = 0;
  sum = num1 + num2;
  return sum;
}

Nested Blocks

for(var i = 0; i < 10; i++){
    for(var j = 0; j < 10; j++){
        console.log(i + ", " + j);
    }    
}