a variable is not defined but i initialized it before

Question

a variable is not defined but i initialized it before

I write a client with nodejs and javascript.when i debug the code the console says that the X1 variable of coordinate is not defined, but i initialized it before.who can explain it for me?

the variable located at "localPlayer = new Player(X1, Y1);" var canvas = document.getElementById("painting");

  var socket;     //Socket connection

   var localPlayer, remotePlayers;     // local and remote players
    var context2D = canvas.getContext("2d");

    var lifecount = 3;     // frogger has three life values
    var score = 0;         // when frogger accross a line successfully it will get 10 points

//initialized the coordinates
function initcoordinates(){

    var pipe0X=0,pipe0Y=110;
    var spider1X= 0,spider1Y=140;
    var spider2X= 0,spider2Y=230;
    var X1=300,Y1=450;     // frogger's ordinary coordinate
    var pipe1X=0,pipe1Y=170;
    var pipe2X= 0,pipe2Y=200;
    var rocketX = 0,rocketY=300;
    var carX = 0, carY =330;
    var wheelX= 0,wheelY=360;
    var car1X= 0, car1Y=390;
    var car2X= 0, car2Y=420;
};

function initimage(){

    var picpipe0 = new Image();
    var pic1=new Image();
    var picpipe1 = new Image();      // pipe image
    var picpipe2 = new Image();
    var spider1 = new Image();
    var spider2 = new Image();
    var gresp1 = new Image();
    var gresp2 = new Image();
    var rocket = new Image();
    var car = new Image();
    var wheel = new Image();
    var car1 = new Image();
    var car2 = new Image();



    //load image
    picpipe0.src = "pipe.jpg";
    pic1.src = "qingwa.jpg";
    picpipe1.src = "pipe.jpg";
    picpipe2.src = "pipe.jpg";
    spider1.src="spider.jpg";
    spider2.src="spider.jpg";
    gresp1.src = "gresp.jpg";
    gresp2.src = "gresp.jpg";

    rocket.src = "rocket.jpg";
    car.src = "car.jpg";
    wheel.src = "wheel.jpg";
    car1.src = "car1.jpg";
    car2.src = "car2.jpg";

};
/**************************************************
** GAME INITIALISATION
**************************************************/
function init(){

initcoordinates();
initimage();

// Initialise socket connection
socket = io.connect("http://localhost", {port: 8000, transports: ["websocket"]});



// Initialise remote players array
    remotePlayers = [];

// Initialise the local player
    localPlayer = new Player(X1, Y1);



// Start listening for events
    setEventHandlers();



}

javascript
node.js

Answer 1

Your X1 variable is locally scoped in the initcoordinates function, it can't be accessed by the init function. Not only the X1 variable is local, but ALL the coordinates you're setting in the initcoordinates function will only be visible inside this function. I suggest you to declare these variables outside, in an immediate function surrounding the others, like this:

(function(){
  var X1;

  function initcoordinates(){
    X1 = ...
  }

  function init(){
    //do something with the X1 variable here...
  }

})();

This way, all your functions will share the access to the variables declared in the scope of your immediate function.