TypeScript two digits addition returns a string concatenation-CodePudding

const x = 1;
const y = ('3' as unknown) as number;

let add = (num1: number, num2: number)=> {
    return num1   num2;
}

console.log(add(x, y));

// prints 13

Where it is supposed to print 4 as "const y" is converted to "number" type

CodePudding user response：

const y = ('3' as unknown) as number; is not converting the string to a number. You are only doing a type assertion here.

So, what JS is doing : 1 '3' = 13.

You would need to do something like Number('3') to fix that issue. But be wary, Number() can return NaN.