To convert a string to an integer in TypeScript, you can use the parseInt() function. This function takes the string as its argument and returns an integer.
Here is an example:
let numStr: string = "42";
let num: number = parseInt(numStr);
console.log(num); // Outputs 42
If the string cannot be converted to an integer, parseInt() will return NaN. Here is an example:
let invalidStr: string = "Hello World";
let num: number = parseInt(invalidStr);
console.log(num); // Outputs NaN
It is also possible to convert a hexadecimal string to an integer using parseInt(). In this case, you need to pass an additional argument to parseInt() to specify the base (16 for hexadecimal). Here is an example:
let hexStr: string = "FF";
let num: number = parseInt(hexStr, 16);
console.log(num); // Outputs 255
Note that if you pass an invalid string or an invalid base argument to parseInt(), the function will also return NaN.