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JavaScript

Posted by Michael Williamson
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Michael Williamson
Front End Web Development Techdegree Graduate 23,903 Points

figuring out an array loop

    this.spaces = [];

    var x, y;
    for (x=1; x <= width; x += 1) {
        this.spaces[x] = [];
        for (y=1; y <= height; y += 1) {
            this.spaces[x][y] = "(" + x + "," + y + ")";                  
        }

    }

}

I'm trying to decode a javascript workshop in treehouse. I'm not quite getting how the [x]in the second for loop can start at 1. I'm restricted to the idea of index starting at zero. anyone have an idea of what's happening here.

1 Answer

james south
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.a{fill-rule:evenodd;}techdegree seal-36
james south
Front End Web Development Techdegree Graduate 33,271 Points
james south
.a{fill-rule:evenodd;}techdegree seal-36
james south
Front End Web Development Techdegree Graduate 33,271 Points

in a nested for loop the outer loop's starting value is maintained until the inner loop completes, so since x=1, x is 1 for the first trip through the inner loop. when that finishes, x increments and the inner loop runs again.

Michael Williamson
.a{fill-rule:evenodd;}techdegree seal-36
Michael Williamson
Front End Web Development Techdegree Graduate 23,903 Points

Where I'm stumped is I'm thinking that the second for loop is building into the array. this.spaces[0][1] is how I would think it should be but in reality its this.spaces[1][1] is how its starting and I'm having trouble with that.