Js detects that the input is all space

2020-03-30 02:49:24
OfStack

JavaScript to determine the input content can not be all space method, to avoid the input box of the contents of the input space:


<html>
 <head>
  <script>
   function checkBlankSpace(str){
    while(str.lastIndexOf(" ")>=0){
      str = str.replace(" ","");
    }
    if(str.length == 0){
     alert(" The input cannot be empty ");
    }
   }
   function test(){
    var testStr = document.getElementById("test").value;
    checkBlankSpace(testStr);
   }
  </script>
 </head>
 <body>
  <input type="text" id="test"/>
  <input type="button" value=" test " onclick="test()">
 </body>
</html>