Notes for compability among browsers

compability.md

JavaScript

.includes()

// IE8 : custom declaration of indexOf()
if(!Array.indexOf){
  Array.prototype.indexOf = function(obj){
    for(var i=0; i<this.length; i++){
      if(this[i]==obj){
        return i;
      }
    }
    return -1;
  }
};
var aList = ['A', 'B', 'C', 'D', 'E'];
// if (aList.includes('D'))
if (aList.indexOf('D') > -1) {
  alert('D!');
}