Commonly Used JavaScript Statements

In this article, we will discuss some of the most commonly used JavaScript statements and provide code examples for each.

var statement

The var statement is used to declare a variable in JavaScript. Variables are used to store data, such as numbers, strings, and objects.

var x = 5;
var y = "Hello World";
var z = {name: "John", age: 30};

let statement

Similar to var, let statement is also used to declare a variable in javascript, but it has a block level scope, unlike var which has a function level scope.

let x = 5;
let y = "Hello World";
let z = {name: "John", age: 30};

const statement

const is also used to declare a variable but it can’t be reassigned after it has been declared.

const x = 5;
const y = "Hello World";
const z = {name: "John", age: 30};

if statement

The if statement is used to execute a block of code if a certain condition is true.

if (x > 5) {
   console.log("x is greater than 5");
}

else statement

The else statement is used in conjunction with the if statement to execute a block of code if the condition in the if statement is false.

if (x > 5) {
   console.log("x is greater than 5");
} else {
   console.log("x is not greater than 5");
}

else if statement

The else if statement is used in conjunction with the if and else statements to test multiple conditions.

if (x > 5) {
   console.log("x is greater than 5");
} else if (x < 5) {
   console.log("x is less than 5");
} else {
   console.log("x is equal to 5");
}

for statement

The for statement is used to execute a block of code a specified number of times.

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

while statement

The while statement is used to execute a block of code while a certain condition is true.

while (x < 10) {
   console.log(x);
   x++;
}

do...while statement

The do...while statement is similar to the while statement, but the code block is executed at least once before the condition is evaluated.

do {
   console.log(x);
   x++;
} while (x < 10);

break statement

The break statement is used to exit a loop or a switch statement.

for (var i = 0; i < 10; i++) {