CODEWITHSUNDEEP
javascriptscope
IGRACH
IGRACH

Reputation: 3635

javaScript for/loop scope

I have written this bit of code that sums the values of array. Can some one please explain why I'm getting undefined in the last console.log statement. 

var array = [2,3,4,5,6,7];
var sum = 0;

for(var i = 0; i < array.length; i++) { 
    sum = array[i] + sum; 
}

console.log(sum);
console.log(array[i]);

Upvotes: 0

Views: 87

Answers (1)

Benjamin Gruenbaum
Benjamin Gruenbaum

Reputation: 276286

That's because the loop performed i++ and now i is equal to array.length.

JavaScript returns the primitive value undefined when you're trying to access object properties that were not previously defined.

The array however is only filled between places 0 and array.length - 1 since JavaScript arrays are 0 based.

Upvotes: 5

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