Javascript why can't i use an array like this and how can i access the array with a calculated number

Question

var nodesXY = ['15% 15%','30% 16%','19% 42%','39% 80%',];
var number  = ["0","1","2","3","4","0","0","0"];

//some loop
    AccesNodes(number[1]);

function AccesNodes(number){
        console.log(number);
        //number = number;
        var firstNode = nodesXY[number];
        console.log(nodesXY[number]);
        console.log(firstNode);
        number++;
        var secondNode = nodesXY[number];
        console.log(nodesXY[number]);
        console.log(secondNode);
        number = number + 4;
        var secondNode = nodesXY[number];
        console.log(nodesXY[number]);
        console.log(secondNode);
    }

I don't get an undefined when I log the firstNode however when I calculate the number into "the next node" and try to get var secondNode = nodesXY[number+1]; I get an undefined. Why won't this work? Is there any other way to get this? I've searched all over.

Dentych · Accepted Answer · 2016-03-23 09:50:25Z

1

Your array number contains elements of type string. Even though JavaScript is not type-strong, variables and elements still contain data of some specific type.

When you access number[X], it will therefore return a string. In order to make it work, you'll have to create an array of numbers: var number = [1,2,3,...] or parse the string returned from the array into a number using parseInt(number[X]).

For a list of the different types a JavaScript var can hold, see this page in the MDN JavaScript documentation.

answered Mar 23, 2016 at 9:50

Dentych

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1 Comment

Thorin Over a year ago

I fixed it in the first comment but this cleared a lot up for me thanks for explaining.

Aliz · Accepted Answer · 2016-03-23 09:38:36Z

1

Use numbers in your number array, not strings

var number  = [0,1,2,3,4,0,0,0];

answered Mar 23, 2016 at 9:38

Aliz

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1 Comment

Thorin Over a year ago

there is a reason i'm using string because im getting an id's from my HTML file which are named #post1 #post2 and i split the number. And after the first comment I used parseInt to number so it worked. but thanks I probably should use my context but my script right now would take to much space to post.

bnord · Accepted Answer · 2016-03-23 09:40:08Z

1

Your numbers array contains strings not actual numbers "1" + 1 will yield "11" instead of 2 which isn't a key in your array. Either use number = [0,1,...] or use parseInt(number) + 1.

answered Mar 23, 2016 at 9:40

bnord

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1 Comment

Thorin Over a year ago

Thanks it worked it's so stupid i didn't think of it. I looked right passed it!

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