PHP字符串切换使用NOT运算符

Question

I have a small switch statement in the header of a portfolio website I'm working on which governs which links are shown on which page. The value of $id comes from the GET variable, ie - '?id=index'.

    switch($id) {
    case "index":
        //Show links to content
    case !"index":
        //Show link to index
    case !"about":
        //show link to about page
}

The issue is that the NOT operator isn't working in the final two cases. I want the link to the index to show when the user is NOT on the index page, and likewise with the about page. Currently, ALL links are shown on the index page (when $id == "index), and NONE are shown on any other pages.

Why might this be?

Answer 1

This is so, because it is supposed to be so.

switch compares using the == operator. So in the second case, you are actually testing whether

$id == (!"index")

Which will always evaluate to false since any string would be trueand not true would be false.

Which means, in your case it would be better to use if and else.