Lets say, I have a string like "150 test". How can I convert this string to a number with the value of 150?
Thanks
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4 Answers
Typescript supports type casting, which you will need in your case if you have your variable types declared.
You simply just want to achieve something like this in JS.
var result = parseInt("125 test");
// result is 125
So, it's possible to cast like follows in typescript,
let msg: String = "125 test";
// If 'msg' is 'String', cast it to 'string' since 'parseInt' argument only accepts 'string'.
let result: Number = parseInt(<string>msg);
// result is 125
This will then be transpiled into js, like;
var msg = "125 test";
var result = parseInt(msg);
4 Comments
gr4viton
Adding type declarations to variables which are immediately assigned is unnecessary, because typescript automatically add the type to the variable under the hood.
gr4viton
Using box types like String and Number is bad practice. Check out typescript official do's and don'ts: typescriptlang.org/docs/handbook/declaration-files/…
choz
@BalázsTakács That's not the case here. Editors or linters are picky about the type definitions in typescript. At least I show him how he can handle them
choz
Actually, that is considered bad practice because of the case like
parseInt above. If OP in fact develops his own codebase with typescript and use boxed types, I don't see why not.An integer number parsed from the given string. If the first character cannot be converted to a number, NaN is returned.
You can use parseInt() which will try to parse the string to number until it gets a non-digit character.
var str = "150 test";
console.log(parseInt(str))Comments
you can use this code snippet:
let str = "150 test";
let result = Number(str.split(" ")[0])
