How to Convert Strings to Numbers in JavaScript

Updated onbyAlan Morel

In this post, we'll learn how to convert strings to numbers in JavaScript.

Let's look at the three different ways you can convert strings to numbers.

parseInt()

The best way to convert a string to a number is to use the `parseInt()` function.

This function accepts two parameters, the string to convert and the optional `radix`.

You can think of the `radix` as the base of the number system, the default being `10`.

Here's an example of how to use the `parseInt()` function:

``````JAVASCRIPTconst number = parseInt("123", 10);

console.log(number); // 123
``````

As mentioned before, the `radix` is optional, so this also works:

``````JAVASCRIPTconst number = parseInt("123");

console.log(number); // 123
``````

parseFloat()

The `parseFloat()` function is similar to `parseInt()`, except it will convert the string to a floating point number, basically a number with decimal points.

Like with `parseInt()`, you can pass a `radix`, which is optional.

``````JAVASCRIPTconst number = parseFloat("123.456", 10);

console.log(number); // 123.456
``````

It will also return the same value without the `radix` parameter:

``````JAVASCRIPTconst number = parseFloat("123.456");

console.log(number); // 123.456
``````

Number()

The third way to convert a string to a number is by using the `Number()` function.

You can think of the `Number()` function as a combination of the previous two functions, except it will always use the `10` radix.

That means if you pass it a string with a decimal point, it will convert it to a floating point number, and if not, it will convert it to an integer.

Here's an example of using `Number()`:

``````JAVASCRIPTconst number1 = Number("123.456");
const number2 = Number("123");

console.log(number1); // 123.456
console.log(number2); // 123
``````

Conclusion

We've covered three different ways to convert a string to a number in JavaScript.

Hopefully, you've found these ways useful for your use-case.