int.TryParse()

double.TryParse()

string stringNumber = "123";
int numericValue;
bool isNumber = int.TryParse(stringNumber, out numericValue); // isNumber is true and numericValue=123 [1](https://www.arungudelli.com/tr/tutorial/c-sharp/check-if-string-is-number/)
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double.TryParse()

string negativeString = "-123";
double number;
if(double.TryParse(negativeString,out number)){
    if (number > 0){
    } else{
        // negative number
    }
}
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