How to convert a String to a Number in TypeScript
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TypeScript is a strongly typed language, which means we have to give things a little more thought when converting between them. Fortunately, converting a string to a number is pretty easy in TypeScript.
Converting a String to a Number in TypeScript
If we’re using integers, the easiest way to convert a string into a number is to simply use the unary (+
) operator. Here is an example using a simple integer:
let someString:string = "4245"
let myNumber:number = +someString;
// Returns 4246
console.log(myNumber + 1);
We can also just use or parseInt
for number-like integer strings:
let someString:string = "4245"
let myNumber:number = parseInt(someString);
// Returns 4246
console.log(myNumber + 1);
Converting Decimals
Unfortunately this method won’t work very well for decimals, as +
and parseInt
deal only with integers. If we want to convert a decimal-like string to a number in TypeScript, we can use parseFloat
, just like normal Javascript:
let someString:string = "4245.1234"
let myNumber:number = parseFloat(someString);
// Returns 4246.1234
console.log(myNumber + 1);
Number function
We can also use the Number
function to convert number-like strings into numbers. This will work with both integers and decimals:
let someString:string = "4245"
let myNumber:number = Number(someString);
// Returns 4246.1234
console.log(myNumber + 1);
More Tips and Tricks for Typescript
- How the TypeScript ReturnType Type works
- How keyof works in Typescript
- Type Casting in TypeScript
- Ultimate Guide to Types in Typescript
- How Typescript Enums Work
- The Difference between TypeScript and Javascript
- How the TypeScript Exclude Type Works
- How the TypeScript Pick Type works
- How the TypeScript Record Type Works
- How the TypeScript Required Type Works