JavaScript true keyword

last modified April 16, 2025

In this article we show how to use the true boolean literal in JavaScript. The true keyword represents one of two possible boolean values in JavaScript.

The true keyword

The true keyword is one of JavaScript's boolean literals, representing the logical true value. It's one of the primitive values in JavaScript along with false, numbers, strings, etc.

Boolean values are fundamental in programming for making decisions and controlling program flow. The true value is often the result of comparison operations or logical expressions.

In JavaScript, true is not the same as truthy values. While many values can be considered truthy in boolean contexts, true is the explicit boolean value representing truth.

Basic true value

The simplest way to use true is as a direct boolean value.

let isActive = true;

if (isActive) {
    console.log("The feature is active");
} else {
    console.log("The feature is inactive");
}

Here we assign true to a variable and use it in a conditional statement. The if statement executes its block when the condition evaluates to true. This demonstrates basic boolean variable usage.

$ node main.js
The feature is active

Comparison returning true

Comparison operations often result in true or false.

let x = 10;
let y = 5;

let result = x > y;
console.log(result);

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

The comparison x > y evaluates to true because 10 is greater than 5. We store this result in a variable and also use it directly in an if statement. This shows how comparisons generate boolean values.

$ node main.js
true
x is greater than y

Logical AND operator

The logical AND operator (&&) returns true when both operands are truthy.

let hasPermission = true;
let isLoggedIn = true;

let canAccess = hasPermission && isLoggedIn;
console.log(canAccess);

if (hasPermission && isLoggedIn) {
    console.log("Access granted");
}

When both variables are true, the AND operation returns true. This is useful for checking multiple conditions that must all be true. The result is stored and used directly in a condition.

$ node main.js
true
Access granted

Logical OR operator

The logical OR operator (||) returns true if at least one operand is truthy.

let isAdmin = false;
let isModerator = true;

let hasPrivileges = isAdmin || isModerator;
console.log(hasPrivileges);

if (isAdmin || isModerator) {
    console.log("User has privileges");
}

The OR operator returns true because one of the operands is true. This demonstrates how to check if at least one condition is met. The operation short-circuits when the first truthy value is found.

$ node main.js
true
User has privileges

Boolean function

The Boolean() function can convert values to their boolean representation.

let value1 = Boolean(1);
let value2 = Boolean("hello");
let value3 = Boolean(true);

console.log(value1);
console.log(value2);
console.log(value3);

The Boolean() function converts truthy values to true. Non-zero numbers, non-empty strings, and true itself all convert to true. This shows explicit boolean conversion.

$ node main.js
true
true
true

Truthy vs true

It's important to distinguish between truthy values and the true boolean.

let value = "hello";

if (value) {
    console.log("The string is truthy");
}

if (value === true) {
    console.log("The string equals true");
} else {
    console.log("The string doesn't equal true");
}

While the string is truthy (causing the first if to execute), it's not equal to the boolean true. This demonstrates the difference between truthy values and the actual true boolean literal.

$ node main.js
The string is truthy
The string doesn't equal true

Default function parameter

The true value can be used as a default parameter in functions.

function greet(name, verbose = true) {
    if (verbose) {
        console.log(`Hello, ${name}! Welcome to our application.`);
    } else {
        console.log(`Hello, ${name}`);
    }
}

greet("John");
greet("Alice", false);

Here we use true as a default value for the verbose parameter. When not specified, verbose defaults to true, showing the full greeting. When set to false, a shorter version is displayed.

$ node main.js
Hello, John! Welcome to our application.
Hello, Alice

Source

Boolean - language reference

In this article we have demonstrated how to use the true boolean literal in JavaScript programming.

Author

My name is Jan Bodnar, and I am a passionate programmer with extensive programming experience. I have been writing programming articles since 2007. To date, I have authored over 1,400 articles and 8 e-books. I possess more than ten years of experience in teaching programming.

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