If Statement
Use the if statement to specify a block of JavaScript code to be executed
if a condition is true.
if (condition) {
// block of code to be executed if the condition is true
}
Example
let x = 10;
if (x > 5) {
console.log("x is greater than 5");
}
Else Statement
Use the else statement to specify a block of code to be executed if the
condition is false.
if (condition) {
// block of code to be executed if the condition is true
} else {
// block of code to be executed if the condition is false
}
Example
let x = 10;
if (x > 5) {
console.log("x is greater than 5");
} else {
console.log("x is less than or equal to 5");
}
Else if Statement
Use the else if statement to specify a new condition if the first condition
is false.
if (condition1) {
// block of code to be executed if the condition1 is true.
} else if (condition2) {
// block of code to be executed if the condition1 is false and
condition 2 is true.
} else {
// block of code to be executed if the condition1 is false and
condition 2 is False.
}
Example
let x = 10;
if (x > 10) {
console.log("x is greater than 10");
} else if (x === 10) {
console.log("x is equal to 10");
} else {
console.log("x is less than 10");
}
Nested if
A nested if is an if statement that is the target of another if or else.
Nested if statements means an if statement inside an if statement. Yes,
JavaScript allows us to nest if statements within if statements. i.e., we can
place an if statement inside another if statement.
if (condition1) {
// block of code to be executed if the condition1 is true.
} if (condition2) {
// block of code to be executed if the condition 2 is true.
}
Example
let num = 15;
if (num > 0) {
console.log("Number is positive");
if (num % 2 === 0) {
console.log("Number is even");
} else {
console.log("Number is odd");
}
} else if (num < 0) {
console.log("Number is negative");
} else {
console.log("Number is zero");
}