I use the identity function in all my JavaScript programs:

```
function identity(value) {
    return value;
}

```

The reason is that I often need differentiate between primitives types (`undefined`, `null`, `boolean`, `number` and `string`) and object types (`object` and `function`) as returned by the `typeof` operator. I feel using the indentity function for this use case very succuint:

```
if (new identity(value) == value); // value is of an object type
if (new identity(value) != value); // value is of a primitive type

```

The identity function is much smaller and simpler than the following code:

```
function isObject(value) {
    var type = typeof value;
    return type == "object" || type == "function";
}

```

However on reading my code a friend of mine complained that my hack is misleading and more computationally expensive than the above alternative.

I don't want to remove this function from any of my programs as I believe it's an elegant hack. Then again I don't write programs solely for myself. Is there any other use case for the identity function in JavaScript?