Adding Methods to array prototype so i can apply it to array object.But it is giving an error TypeError: Array.method is not a function

Question

I am trying add a method to Array prototype.But it is giving me an error TypeError: Array.method is not a function

I am trying this example from JavaScript: The Good Parts.

Here is a piece of my code.

    Array.method('reduce',function(f,value){
      var i;
      for(i=0; i < this.length; i+1){
        value = f(this[i],value);
      }
      return value;
    });


    var data = [1,3,2,4,5,6,7,8,9];

    var add = function(value1, value2){
      return value1 + value2;
    }

    var result = data.reduce(add, 0);

    console.log(result);

I want to apply the reduce method to data array. So i can do addition ,multiplication on array and return the result.

Answer 1

Most of the code you have tried is correct. I think you are trying to add all the elements and return using reduce function to array. But to achieve what you wanted,checkout fiddle link:

http://jsfiddle.net/x2ydm091/2/

Array.prototype.reduce=function(f, value){
    for(var i=0;i< this.length;i++){
        value=f(this[i],value);
    }
    return value;
};

var add = function(a,b){
    return a+b;
}

var data = [1,3,2,4,5,6,7,8,9];
var result = data.reduce(add,0);
alert(result);

Hope that helps!