Question

I want to make a button to start the onclick to make the random numbers keep running,(use

1. or 2. to call) but if I press it , the error message shows that “Uncaught

ReferenceError: spanArray is not defined” but above the number is still running, I cannot

understand where is the wrong place.

PS But if I use 3 it work normally.

Thx!

thx complete code I try by 3 is http://jsfiddle.net/eVyjC/

function computeRandom(){
// skip code: have used loop to create six spans already
var spanArray = document.getElementsByTagName("span");
//1.document.write("<input type =  button  value = 'start' onclick = \"passKeepMove(value,spanArray) \"  name = button1>");
//2.document.write("<input type =  button  value = 'start' onclick =  \"setInterval(function(){keepMove(value,spanArray);}, 10) \"  name = button1>");
//3.setInterval(function(){keepMove(value,spanArray);}, 10) ;
   }


function keepMove(val,sp){//call by pointer 

    var index = parseInt(Math.random()*43);//set a increment to avoid repeatition

    for( i = 0; i < sp.length; i++){
    sp[i].innerHTML = val[i+index];
    }
}


function passKeepMove(v,s){
    setInterval(function(){keepMove(v, s);}, 10);
}

Answer 1

The var in front of var spanArray is making spanArray a local variable. So you can not access it outside of computeRandom‘s function scope.

You need to make it global or come up with a better design so you do not need global variables.