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Friday, June 17, 2016

Some coding problems to practice using Underscore functions

1.  Take this array of objects and extract out the values of a particular property from each of them.

Use can use this array:

var arrayObj = [{name: "Johen", age: 7}, {name : "Brian", age : 8}, {name: "Sam", age: 98}, {name : "Jules", age : 89}];


2. Build a function that will take an array of objects, and return the number of times a particular value in each object passes a truth test.

  For example, let's say, in the above array named arrayObj, that I wanted to count how many people are over 18.

  My function has three parameters, collection, key, age .  So, I can put enter in any age I like, and get the number of people over that age returned to me, as a number.  The above array returns 2 in my function if I use 18 as age.


Solution in the comments.




1 comment:

  1. var countAge = function(array, key, age ){
    var counter = 0;
    if(_.each(_.pluck(array, key), function(item){
    if (item > 18){
    counter ++;
    }
    }));



    return counter;
    }

    ReplyDelete