2具有相同类名的命名空间 - 是否需要使用“use”别名来调用第一个命名空间？

From my below code, I try to call the sayHi method, in class Cat with namespace foo; but it not work, I have to use "use" to change name to call it;

    <?php

    namespace foo;

    class Cat
    {
        public static function sayHi()
        {
            echo "Meow";
        }
    }

    namespace bar;

    class Cat
    {
        public static function sayHi()
        {
            echo "Hello";
        }
    }


    foo\Cat::sayHi();  //try to use backslash path  but Fatal error: Class 'bar\foo\Cat' not found

?>

if I use Cat::sayHi(); it always call the method from namespace bar that I don't want. so Question: Are there any method that solve this problem without use 'use' alias?

When you declare a namespace, your code operates within that namespace until you declare another, or until the end of the file. You're doing this:

namespace foo;
class Cat {}
namespace bar;
class Cat {}
// here you are in namespace bar
foo\Cat::sayHi();

Since you're already in the bar namespace, and your namespace reference doesn't anchor the root namespace, this final line is interpreted as:

\bar\foo\Cat::sayHi();

Simply anchor to the root:

\foo\Cat::sayHi();

Or put your call to foo\Cat::sayHi(); in another file.