JS - ProtoType

Array

//Array . prototype

Array.prototype.every = function(f){
  //isevery = false; // intially set to false
  for(let i=0;i<this.length;i++)
    if(!f(this[i])) return false; // onfailing it returns false    
  return true;
}

Array.prototype.some = function(f){
  issome = false; // intially set to false
  for(let i=0;i<this.length;i++)
    if(f(this[i])) return !issome;
  return issome;
}

//some.call([1,2,3],(a)=>{return a>3;})
//every.call([1,2,3,4],(a)=>{return a+1>-1})