CODEWITHSUNDEEP
javascript
YoniGeek
YoniGeek

Reputation: 4093

Why do I I get undefined in this calculation in JavaScript?

I try to loop through the whole array and find out how 'true' they are. Now when I run the function I get some undefined-result. :( Why?

myArray = [
    {text: 'hola', done: false},
    {text: 'hola', done: true},
    {text: 'hola', done: true},
    {text: 'hola', done: false},
    {text: 'hola', done: true}
  ];

  var howMany = function(myArray){

     var result;
      for (var item in myArray){
          if(myArray.done === true)
            result++;
      }
      return result;
  };


var items =howMany(myArray);
    console.log(items) // I want to see if it's correct

Upvotes: 0

Views: 86

Answers (3)

Niko
Niko

Reputation: 26730

a) You did not initialize the value of result:

var result = 0;

b) This is not how you iterate over the items of an array:

for (var i = 0; i < myArray.length; i++) {
    var item = myArray[i];
    if (item.done === true) { // <-- "item" here, not "myArray"!
        result++;
    }
}

Upvotes: 5

VisioN
VisioN

Reputation: 145398

Check that result variable is initialised with 0. And there is another problem in iteration. You need to use myArray[item] to get the value of the object property:

if (myArray[item].done === true)

Upvotes: 4

Niet the Dark Absol
Niet the Dark Absol

Reputation: 324640

Try initialising your variable to an actual value: var result = 0;

EDIT: Also, as per VisioN's answer, you need to check myArray[item].done

Upvotes: 1

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