SOURCE

var a = ["a","b","c","d"]
  var b = [];
  var c = [1000,200,1300,400];
for(var i=0;i<a.length;i++){
    var t = a[i];
    b.push(
      new Promise((function(resolve,reject){
        setTimeout(()=>{
          console.log(this.t,this.i)
          resolve();
        },c[i])
      }).bind({t:t,i:i}))
    )
  }