如何在布尔值的子类化中更改字符串表示形式，而又不会在函数外部产生负面影响？

Question

I need to a way to wrap a boolean value such that comparisons are not broken and the string result is different than 'false' or 'true' without altering the global boolean values

function TestIt(bool){
    if(wrapper(bool) == true)
        return "it was: " + wrapper(bool)
    if(wrapper(bool) == false)
        return "it was: " + wrapper(bool)
    return "no dice"
}

eg

var result;
result = TestIt(true);
// "it was: True"
result = TestIt(false);
// "it was: False"

The attempts I have written have not been able to achieve all of the conditions below at the same time:

var initial = true;
var result1;
var result2;
(function(){
    result1 = wrapper(true);
    result2 = wrapper(true);
})()
// result1 == result2
// result1 == true
// result1.toString() != initial.toString()
// initial.toString() == true.toString()
// initial.toString() == (new Boolean(true)).toString()

Can anyone help me please?

I need this (automatic) alternate string conversion so that I can duplicate a string created on a server environment using a different language and match it exactly.

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Edit

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I forgot to mention that the trouble I am running into is the Boolean "valueOf" method that is called instead of toString (apparently) for string concatenation.

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Edit #2

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This would also need to work for false. I just left that out for brevity. However, wrapper(false) == false gave me a headache.

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Edit Final

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It turns out (in the answers below), that you can't override the default behavior like I wanted if string concatenation is used. I am going to work on using an array to solve my problem and then doing custom conversions when I join it back together. It seems like Javascript requires an oddball approach to a conceptually simple problem.

Code Example for command line:

function boolish(a){a=new Boolean(a);a.toString=function(){return this.valueOf()?"True":"False"};return a};

boolish(false) == false
boolish(true) == true
boolish(false) + " or " + boolish(true)
[boolish(false) , " or " , boolish(true)].join("~~~~~~~~")

Answer 1

I don't understand why you think you need this to happen automatically via toString() . If you have a "plain" boolean you can (obviously) use it in any comparisons as normal, but if you want to get some non-standard text when concatenated just specify it at the time. For example, if you wanted "TRUE" and "FALSE" all in caps:

var myBool1 = false,
    myBool2 = true;

alert("The value of myBool1 is: " + (myBool1?"TRUE":"FALSE"));

Or you could write a little function:

function boolToString(val) {
   return val ? "True enough" : "That's a lie!";
}

alert("The value of myBool2 is: " + boolToString(myBool2));

EDIT According to the following SO question (and answers): valueOf() vs. toString() in Javascript your requirement can't be done. The string concatenation + operator will always end up using valueOf rather than toString . I agree that this is weird. The workaround is to concatenate the strings without using the + operator, but I gather you don't want to do that.

Answer 2

You can do something like:

function myBool(value) {
  this.value = value;
}
myBool.prototype.toString = function() {
  return 'The value is ' + (this.value? 'true' : 'false');
}

var x = new myBool(true);

alert(x);  // 'The value is true'