Why would there be a undefined at the end of this array?

Question

I'm trying to make a simple array with random text. I always see undefined after the end of the array though. Is there any way to remove it? I've searched and tried [i-1], but no luck.

function arrayMaker(integer) {
var alphabet = "abcdefghijklmnopqrstuvwxyz";
var array = [];
for (q = 0; q < integer; q++){
    var word = '';
    for (i = 0; i < Math.floor((Math.random() * 10) +1); i++){
        var number = Math.floor(Math.random() * 26);
        word += alphabet.substring(number, (number+1));
    }
array.push(word);
}
console.log(array);
}
var test = arrayMaker(10)
console.log(test)

Nina Scholz · Accepted Answer · 2016-04-18 08:46:54Z

5

You do not return something. Add

return array;

Then you get the array, you want.

If you use just return or no return, then undefined is returned.

function arrayMaker(integer) {
    var alphabet = "abcdefghijklmnopqrstuvwxyz",
        array = [], q, i, number, word;
    for (q = 0; q < integer; q++) {
        word = '';
        for (i = 0; i < Math.floor((Math.random() * 10) + 1) ; i++) {
            number = Math.floor(Math.random() * 26);
            word += alphabet.substring(number, (number + 1));
        }
        array.push(word);
    }
    return array;
}
var test = arrayMaker(10);

document.write('<pre>' + JSON.stringify(test, 0, 4) + '</pre>');

edited Apr 18, 2016 at 8:46

answered Apr 18, 2016 at 8:43

Nina Scholz

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1 Comment

Walfrat Over a year ago

To be more precise : the undefined that you see is the value of your test variable. The others displayed log are those of console.log(array).

yojna · Accepted Answer · 2016-04-18 09:02:42Z

0

You are not returning any value from the function, that's why it is showing undefined. Variable "test" does not have any data.

Try this:

function arrayMaker(integer) {
 var alphabet = "abcdefghijklmnopqrstuvwxyz";
 var array = [];
 for (q = 0; q < integer; q++){
    var word = '';
    for (i = 0; i < Math.floor((Math.random() * 10) +1); i++){
    var number = Math.floor(Math.random() * 26);
    word += alphabet.substring(number, (number+1));
    }
    array.push(word);
 }

 console.log(array);
 return array;
}
var test = arrayMaker(10)
console.log(test)

answered Apr 18, 2016 at 9:02

yojna

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