gistfile1.js

function Graph(width, length) {
    this.width = width;
    this.length = length;
    this.elements = 2; // I want to keep this
    this.nodes = new Array(width * length);
    
    var i;
    for (i = 0; i < this.nodes.length; i += 1) {
        this.nodes[i] = new Node(this, i);
    }
}

Graph.prototype.save = function () {
    return JSON.stringify(this, replacer, 4);
};

function replacer(key, value) {
    var excludes = ["graph", "elements"];
    if (excludes.indexOf(key) >= 0) {
        return undefined;
    }
    return value;
}

function Node(graph, index) {
    this.graph = graph; // Exclude from JSON
    this.index = index;
    this.elements = []; // Exclude from JSON
}

var world = new Graph(9, 4);