Boolean.prototype.toString()

The toString() method of {{jsxref("Boolean")}} values returns a string representing the specified boolean value.

{{InteractiveExample("JavaScript Demo: Boolean.prototype.toString()")}}

```js interactive-example const flag1 = new Boolean(true);

console.log(flag1.toString()); // Expected output: "true"

const flag2 = new Boolean(1);

console.log(flag2.toString()); // Expected output: "true"

## Syntax

```js-nolint
toString()

Parameters#

None.

Return value#

A string representing the specified boolean value.

Description#

The {{jsxref("Boolean")}} object overrides the toString method of {{jsxref("Object")}}; it does not inherit {{jsxref("Object.prototype.toString()")}}. For Boolean values, the toString method returns a string representation of the boolean value, which is either "true" or "false".

The toString() method requires its this value to be a Boolean primitive or wrapper object. It throws a {{jsxref("TypeError")}} for other this values without attempting to coerce them to boolean values.

Because Boolean doesn't have a [Symbol.toPrimitive]() method, JavaScript calls the toString() method automatically when a Boolean object is used in a context expecting a string, such as in a template literal. However, boolean primitive values do not consult the toString() method to be coerced to strings — rather, they are directly converted using the same algorithm as the initial toString() implementation.

Boolean.prototype.toString = () => "Overridden";
console.log(`${true}`); // "true"
console.log(`${new Boolean(true)}`); // "Overridden"

Examples#

Using toString()#

const flag = new Boolean(true);
console.log(flag.toString()); // "true"
console.log(false.toString()); // "false"

Specifications#

{{Specifications}}

Browser compatibility#

{{Compat}}

See also#

• {{jsxref("Object.prototype.toString()")}}