CODEWITHSUNDEEP
javascriptarrays
Burak
Burak

Reputation: 9

Javascript Arrays

var myArray = ['burak', 'mirhan', new Date(), 'ibrahim'];


for (var i = 0; i <= myArray[i].toString ().length; i++) {
    alert (myArray [i].toString ().length); 
}

ı wrote the code above. it works. but firebug alerts that "myArray[i] is not defined". I can't solve it. Can you help me on this ? As you can understand I am little bit noob on javascript. I am trying to learn so thank you for your help.

Upvotes: 0

Views: 120

Answers (4)

Eric
Eric

Reputation: 97691

When you iterate over an array, you should be simply be looking at the length of the array, not the length of the string in the current element of the array:

for (var i = 0; i < myArray.length; i++)

Upvotes: 4

nnnnnn
nnnnnn

Reputation: 150080

In JavaScript, array indices start at 0, and an array's .length property will be one higher than the current highest element index. So for your array with four contiguous elements the .length will be 4 and the element indices are 0, 1, 2 and 3.

You need to set up your loop to run from 0 to .length - 1, so use i < myArray.length rather than i <= myArray[i].toString ().length:

for (var i = 0; i < myArray.length; i++)

The reason you though your code was working other than that error is that because you had i <= myArray[i].toString ().length it was testing i against the length of the toString() values of elements in the array rather than against the length of the array itself. So on the first iteration when i was 0 it would test if 0 is less than or equal to the length of the first element in the array, on the second iteration it tests if i is less than the length of the second element, and so forth. Because all items in your array had a .toString().length greater than the length of the array itself your loop did iterate through all of the elements, but then when i got to 4 it tried to test an element that didn't exist.

Upvotes: 2

Evan Trimboli
Evan Trimboli

Reputation: 30092

Assuming you want to loop over each item in the array, you need to get the array length:

var myArray = ['burak', 'mirhan', new Date(), 'ibrahim'];


for (var i = 0; i < myArray.length; i++) {
    alert (myArray [i].toString ().length); 
}

Upvotes: 1

flavian
flavian

Reputation: 28511

var myArray = ['burak', 'mirhan', new Date(), 'ibrahim'];


for (var i = 0, len = myArray.length; i < len; i++) {
    console.log(myArray[i]);
};

If you are a JS efficienado:)

Upvotes: 2

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