JavaScript If Statement

1. Basic Syntax

The syntax for an if statement is as follows:

if (condition) {
    // code to be executed if condition is true
}

Here, condition is an expression that evaluates to true or false.

2. Example of an If Statement

Here’s a simple example of using an if statement:

const age = 18;

if (age >= 18) {
    console.log('You are an adult.');
}

In this example, since the age variable is 18, the message "You are an adult." will be logged to the console.

3. If-Else Statement

You can also use an else clause to execute code when the condition is false.

if (age >= 18) {
    console.log('You are an adult.');
} else {
    console.log('You are a minor.');
}

In this case, if age is less than 18, "You are a minor." will be logged.

4. Else If Statement

You can chain multiple conditions using else if:

if (age < 13) {
    console.log('You are a child.');
} else if (age < 18) {
    console.log('You are a teenager.');
} else {
    console.log('You are an adult.');
}

This example checks for three different age ranges and logs the appropriate message.

5. Nested If Statements

You can also nest if statements within each other:

const score = 85;

if (score >= 60) {
    console.log('You passed!');
    if (score >= 90) {
        console.log('Excellent job!');
    }
} else {
    console.log('You failed.');
}

Here, if the score is 90 or above, it will log "Excellent job!" in addition to "You passed!".

6. Conclusion

The if statement is a fundamental building block for conditional logic in JavaScript. By using if, else, and else if statements, you can control the flow of your code based on different conditions.