如何检查用户不能在HTML网页中输入多个小数点或点

Question

我有一个带有输入字段的网页，我希望用户可以在其中输入数字，但数字不能包含两位小数，例如10.0.0，意味着它只能输入。一次而不是我们如何解决此问题的两倍。

Answer 1

  function run(element) {
            var regex = /\d*\.?\d?/g;
            element.value = regex.exec(element.value);

    }

call this function on keypress

Answer 2

You could handle the event of the keypress or keyup and check if the key pressed is a dot. If it is entered the first time, you could assign a boolean centinel to true, and cancel the keypress event for future dots.

Answer 3

Presuming input element el is already assigned to a variable v.

if (1 < v.match(/\./g).length) {
  alert("Multidots found");
}

Answer 4

Try using

var str = '10.0.0';
str.indexOf('.');

which gives how many times its contain in a string.