Question

68

How prevent whitespace in input field with plain javascript

rated 0 times [ 75] [ 7] / answers: 1 / hits: 29601 / 9 Years ago, thu, september 3, 2015, 12:00:00

I have an username input field and trying to prevent user fill them with white spaces.

<input type=text name=username />

i do this and whitespace isn't blocked

var

  field = document.querySelector('[name=username]');



field.addEventListener('keypress', function ( event ) {  

   var 

     key = event.keyCode;



   return (key !== 32);

});

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4 Years ago

answered 9 Years ago darrylm · Accepted Answer

Use event.preventDefault to prevent its default behavior.

var field = document.querySelector('[name=username]');



field.addEventListener('keypress', function ( event ) {  

   var key = event.keyCode;

    if (key === 32) {

      event.preventDefault();

    }

});

<input type=text name=username />

If you want to use the return false;, then you should use the onkeypress of the input instead, jsfiddle

field.onkeypress = function(e) {

   var  key = e.keyCode;

   return (key !== 32);

};