JSFiddle - React, Tailwind, and code Playground

HTML

<input class="yourClassName" type="text" defaultValue="To search, type and hit enter"/>
<input class="yourClassName" type="text" defaultValue="To fly, get a pilot's license."/>

JavaScript

var elements = document.querySelectorAll('.yourClassName');
for(var i = 0, j = elements.length; i < j; i++) {
   var element = elements[i]; 
   element.onfocus = function() {
      this.value = '';
      this.style.color = 'black';
   };
   element.onblur = function() {
       if(this.value == '') {
          this.value = this.getAttribute('defaultValue');
          this.style.color = 'grey';
       }
   };
   element.onblur();
}