JavaScript determines the input box can only enter a number of methods

JavaScript only allows you to enter numbers in a number of ways, summarized below

1, only numbers and decimal points are allowed.

<onKeypress= "return (/[\d.) /.test (string.fromcharcode (event.keycode))) "  style=" ime-mode:disabled ">

2, judge the more detailed some, even 22. 2 That's not a number.

<script> <br>function check () {<br>    var i=document.getelementbyid ("tt"). Value;<br>    if (isNaN (i)) {<br>        alert ("illegal character! "); <br>        tt.value= "";<br>    } <br>} <br></script> <br><input type= "text" Name= "tt" id= "tt" onkeyup= "check ();" >

3, only integer input is Allowed. In fact, we can also make some restrictions according to the third article Extrapolate.

<script language=javascript>function  onlynum () {    if(!) ( Event.keycode==46) &&! (event.keycode==8) &&! (event.keycode==37) &&! (event.keycode==39))     if (! ((event.keycode>=48&&event.keycode<=57) | | (event.keycode>=96&&event.keycode<=105)))    Event.returnvalue=false;}

<onkeydown= "onlynum ();" style = "ime-mode:disabled" >

4, only a Number.

<onkeyup= "value=value.replace (/[^\d]/g, ')"  onbeforepaste= " Clipboarddata.setdata (' text ', clipboarddata.getdata (' text '). replace (/[^\d]/g, "))">

conclusion, In fact style= "ime-mode:disabled This sentence is more practical." Turn off the Ime. The best effect is 3, you can directly prohibit the input, 4 is the input after the replacement, so that the input has the opportunity to press enter, there will be unexpected results.

JavaScript determines the input box can only enter a number of methods