implementation of if command in variables

Question

here is my code:

var a=false;
var b=false;
var c=true;
var d=false;
//
var x = a ? a : (b ? b : (c ? c: false)) ;
//
for(i=0;i<11;i++){
    document.write(x);
}

the inline if command check's which variable (a,b,c) is true then equal's x to that
and in the loop it will write that 10 times
there are two assumptions:

• first: it will execute if command 10 times in loop to get final value of x
• second: it will execute if command just one time just into x at first and in loop x will be just a variable containing true
  
  which one is true?
  thanks

Answer 1

it contains a typo anyway, to be sure it should rather look like :

var x = a ? a : (b ? b : (c ? c: false)) ;

so you could test it like:

var a=false;
var b=false;
var c=false;
var d=false;

var x = a ? a : (b ? b : (c ? c: "everything false")) ;


function runTest(){
    for(i=0;i<11;i++){
        console.log(x);
    }   
}

so when you runTest() is will log "everything false" changing the variable b=true in console, e.g without refreshing the page, so your scenario and runTest() again it will still prin "everything false"

so the answer is

once x is assigned the expression, x IS the result of the expression and not the expression itself, and when you print x some later it still is the same result, even if the result of the expression now would be different ( because some gobal variables changed )

to let x always be "up to date" make it a function

x = function () {
  return a ? a : (b ? b : (c ? c: false)) ;
}

then it would evaluate on every call