HTML输入框仅包含特定数字

Question

I need an input text-box that can accept only string of 0's and 1's like 00101110101.

<input type="number"></input> restricts any letters to be entered, however, we can input 1,2,3,4 and so on. I need to restrict input string to consist only 0's and 1's.

Any way to do in HTML or with Javascript aid?

Answer 1

You can use a regular expression ( /[^01]/g ) and replace to remove anything except 0 and 1 from the input's value.

 document.getElementById("inp").oninput = function() { var v = this.value; // get the value from the input v = v.replace(/[^01]/g, ''); // replace anything that isn't 0 or 1 by '' this.value = v; // set the value of the input to the new value } 

 <input id="inp"/> 

If you want the user to still edit things in the middle, then use this:

 document.getElementById("inp").oninput = function() { var pos = this.selectionStart; // save the position of the caret var v = this.value; v = v.replace(/[^01]/g, ''); this.value = v; this.selectionStart = pos; // restore it this.selectionEnd = pos; // so no text will be selected } 

 <input id="inp"/> 

Note that I don't recommend using this last approach, as I'm not sure how many browsers handle selectionStart and selectionEnd .

Answer 2

This may help you.

<input type="text" onkeypress='return event.charCode >= 48 && event.charCode <= 49'>

Hope it will help. Regards.