参数进行值传递的方式有三种，分别是传值(value)，传址(address)，和传引用(reference)



传值时子函数（被调用者）复制父函数（调用者）传递的值，这样子函数无法改变父函数变量的值



传址时父函数将变量的地址传递给子函数，这样子函数可以能过改写地址里的内容改变父函数中的变量



传引用则是一种看起来像传值调用，而实际上功能同传址一样的传递方式。子函数可以改写父函数的变量值。-Parameters are passed by value in three ways, namely by value (value), pass the address (address), and pass references (reference) return value Functions (callee) function copies the value of the parent (caller) passed, Functions such sites can not change the value of the transfer function of the parent function parent variables passed to the subroutine address variable, so too may be able to rewrite the subroutine address the contents of the change in the parent function is a variable passed by reference looks like call by value, and in fact the same address with the transfer function transfer mode. Functions can be rewritten parent function of the variable value.