在javascript中的文字函数中更改变量的值

Question

I'd like to know how to get this result:

function() {
   var myVar = "";
   function () {
      myVar += "This is ";
   }
   myVar = "my string";
   alert(myVar); //would like it to display: This is my string
   // only displays: my string
}

Answer 1

You A. have to call a function for it to execute and B. must reorganize you string a bit

function() {
   var myVar = "";
   function update() {
      myVar = "This is " + myVar;
   }
   myVar = "my string";
   update();
   alert(myVar); //would like it to display: This is my string
   // only displays: my string
}

Answer 2

You have to call the function.

var myVar = "";
function someFunction() { // Give it a name
   myVar += "This is ";
}
myVar = "my string";
someFunction(); // and call it
alert(myVar);