isinteger

问题 Say I've got a string which contains a number. I want to check if this number is an integer. Examples IsInteger("sss") => false IsInteger("123") => true IsInterger("123.45") =>false 回答1: You can use int.TryParse. It will return a bool if it can parse the string and set your out parameter to the value int val; if(int.TryParse(inputString, out val)) { //dosomething } 回答2: There are two immediate options that you can use. Option 1 - preferred - use Int32.TryParse. int res; Console.WriteLine(int

问题 I can think of several ways, eg. Convert.ToInt32(floatingPoint) - floatingPoint == 0; Math.Truncate(floatingPoint) - floatingPoint == 0; floatingPoint % 1 == 0; Math.Floor(floatingPoint) == floatingPoint; //etc... But which method is most reliable? 回答1: You should not check for exact equality to zero, as a floating point number usually only contains the closest possible approximation to the number that you assigned to it. For example, the closest possible value to 42 that the type could

问题 Number.prototype.isInteger = Number.prototype.isInteger || function(x) { return (x ^ 0) === x; } console.log(Number.isInteger(1)); will throw error in IE10 browser 回答1: Apparently, IE treats DOM objects and Javascript objects separately, and you can't extend the DOM objects using Object.prototype. IE doesn't let you use a prototype that is not native.. You'll have to make a separate function (global if you want) as function isInteger(num) { return (num ^ 0) === num; } console.log(isInteger(1)