javascript全局变量在函数内部未定义

Question

For some reason a JavaScript global variable becomes undefined inside function when set to local variable sometime. For example, in below sample the local often become " undefined ". Could anyone of you please advise?

I'm expecting the value of " local " is "global value" in functionB() and functionC() or doStringProcessingA() and doStringProcessingB() . The value of " local " is " undefined ". I'm sure there's no other places assign value or set undefined to global in anywhere.

I've checked below links, but it seems not related. 'Hoisted' JavaScript Variables and Why a variable defined global is undefined?

functionA() was called by onClick event from HTML.

 var global;

 function functionA(){
    global = "global value";
 }

 function functionB(){
    var local = global;     
    doStringProcessingA(local);
 }

 function functionC(){
    var local = global;     
    doStringProcessingB(local);
 }

<div onclick="functionA()">
    <span class="Text">Submit</span>
</div>

Answer 1

Can you try this

Var global = "text";
function  functA{
     Var lol = global; 
     dostringprocess(local);
  }

I think in your code it taking local variable from FunctioA, and also you can check in two ways

1) open console and see the log what error it showing exactly by putting some log message in every function in function stack

2) you can use closure

Answer 2

since your global value is defined under a functionA() so when you call a function B() or functionC() directly your global variable does not contain any value.. so for this you have to intialise the value of global variable..

var global="Earth";                      // now it will not give any errror

 function functionA(){
    global = "global value";
 }

 function functionB(){
    var local = global;     
    doStringProcessingA(local);
 }

 function functionC(){
    var local = global;     
    doStringProcessingB(local);
 }

<div onclick="functionA()">
    <span class="Text">Submit</span>
</div>