How to convert a string to number in typescript?

In this article, we will discuss how we can convert a string to a number in typescript by using various methods and examples.

we can convert a string to a number in Typescript by using the following methods:

1. using Unary Plus (+) operator
2. parseInt( ) function
3. parseFloat( ) function
4. Global number( ) function

convert string by using unary operator

In this code, we will convert string to number by using the '+' Unary Operator.

a unary operator will convert all the strings representing of numbers like '123', True, False, etc into numbers. for True it will convert it into 1 and for false it will be 0.

let str = "540";
console.log('type of str before converting:',typeof str);
let num = +str;
console.log('after converting str becomes:',typeof num);
console.log(num);
console.log(+true);
console.log(+false);

type of str before converting: string
after converting str becomes: number
540
1
0

Convert string into number using parseInt( ) function

parseInt( ) function will convert string representing number into integer form.

let str = "540";
console.log('before converting type:', typeof str);
let num = parseInt(str);
console.log('after converting type:', typeof num);

 before converting type: string
after converting type: number

Convert string into number using parseFloat( ) function

if the string contains a floating point value then use parseFloat() instead of parseInt().

parseFloat( ) function will convert string representing floating point number into float number.

let str = "540.5";
console.log('before converting type:', typeof str);
let num = parseFloat(str);
console.log('after converting type:', typeof num);
console.log(num)

before converting type: string
after converting type: number
540.5

Converting strings into numbers using the Number( ) function

Number() function is one of the best functions for converting strings into numbers. it is like + unary operator. 

let str = "540.5";
console.log('before converting type:', typeof str);
let num = Number(str);
console.log('after converting type:', typeof num);
console.log(num)
console.log(Number(true))
console.log(Number(false))
console.log(Number("40"))
console.log(Number("50.5"))

before converting type: string
after converting type: number
540.5
1
0
40
50.5