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JavaScript Object-Oriented JavaScript: Part 1

Posted by Sheikh Mahmud
Sheikh Mahmud
51 Points

After I put m.setWall(1,3,"north"), why it return undefined? I did exactly as Randy did and still no good. Please help.

No clue

David Evans
David Evans
10,490 Points

Would need to see your code and the error message to help.

I see the code you added. What is the error message in your console that you're getting? What is undefined? I've run all this locally and I am able to type 'm' in the console and see the correct output.

I've cleaned up your code a bit for any future readers:

robot.html

<!DOCTYPE html>
<html>
<head>
    <script type="text/javascript" src="robot.js"></script>
    <script type="text/javascript" src="maze.js"></script>
    <script type="text/javascript" src="mazespace.js"></script>
    <script>
        m = new Maze(7,5);
        m.setStart(1,1,"north");
        m.setEnd(7,1);
        m.setWall(1,1,"east");
    </script>
</head>
<body>
    <div id="page">
        Loading...
    </div>
</body>
</html>

maze.js

"use strict";

function Maze(width, height) {

    this.width = width;
    this.height = height;

    this.startX = null;
    this.startY = null;
    this.startOrientation = null;
    this.endX = null;
    this.endY = null;

    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] = new MazeSpace();
        }
    }
}

Maze.prototype.setStart = function (x, y, orientation) {
    this.startX = x;
    this.startY = y;
    this.startOrientation = orientation;
};

Maze.prototype.setEnd = function (x, y) {
    this.endX = x;
    this.endY = y;
};

Maze.prototype.setWall = function (x, y, direction) {
    if (x > 0 && x <= this.width && y > 0 && y <= this.height && ["north", "east", "south", "west"].indexOf(direction) !== -1) {
        this.spaces[x][y].setWall(direction);
        return true;
    }
    return false;
};

You did not include robot.js or mazespace.js but I'll include them from what I saw in the video. I'm assuming you have them. If not, this is most likely your problem.

mazespace.js

"use strict";

function MazeSpace(directions) {
    this.north = false;
    this.east = false;
    this.south = false;
    this.west = false;
}

MazeSpace.prototype.setWall = function(direction) {
    this[direction] = true;
}

robot.js

"use strict";

function Robot() {
    this.x = null;
    this.y = null;
    this.orientation = null;
    this.maze = null;
}

Robot.prototype.setMaze = function(maze) {
    this.maze = maze;
    this.x = maze.startX;
    this.y = maze.startY;
    this.orientation = maze.startOrientation;
};

Robot.prototype.turnRight = function() {
    if (!this.maze || !this.maze.isValidDirection(this.orientation)) {
        return false;
    }

    var rights = {
        north: "east",
        east: "south",
        south: "west",
        west: "north"
    }
    this.orientation = rights[this.orientation];
    return true;
}

Robot.prototype.turnLeft = function() {
    if (!this.maze || !this.maze.isValidDirection(this.orientation)) {
        return false;
    }

    var lefts = {
        north: "west",
        east: "north",
        south: "east",
        west: "south"
    }
    this.orientation = lefts[this.orientation];
    return true;
}

3 Answers

Sheikh Mahmud
Sheikh Mahmud
51 Points
Sheikh Mahmud
Sheikh Mahmud
51 Points

Okie dokie

Sheikh Mahmud
Sheikh Mahmud
51 Points
Sheikh Mahmud
Sheikh Mahmud
51 Points

this is the maze.js file

"use strict";

function Maze(width, height) { this.width = width; this.height = height;

this.startX = null;
this.startY = null;

this.startOrientation = null;
this.endX = null;
this.endY = null;


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] = new MazeSpace();
    }
}

}

Maze.prototype.setStart = function (x, y, orientation) { this.startX = x; this.startY = y; this.startOrientation = orientation; };

Maze.prototype.setEnd = function (x, y) { this.endX = x; this.endY = y;

};

Maze.prototype.setWall = function (x, y, direction) { if (x > 0 && x <= this.width && y > 0 && y <= this.height && ["north", "east", "south", "west"].indexOf(direction) !== -1) { this.spaces[x][y].setWall(direction); return true; } return false; };

Sheikh Mahmud
Sheikh Mahmud
51 Points
Sheikh Mahmud
Sheikh Mahmud
51 Points

Robot.html file

<!DOCTYPE html> <html> <head>

<script type="text/javascript" src="robot.js"></script>
<script type="text/javascript" src="maze.js"></script>
<script type="text/javascript" src="mazespace.js"></script>

<script> m = new Maze(7,5); m.setStart(1,1,"north"); m.setEnd(7,1); m.setWall(1,1,"east");

</script>

</head> <body>

<div id="page">
    Loading...
</div>

</body> </html>