我想在类中创建一个函数,来创建用户名,函数将检查用户名是否存在,然后它将增加用户名,例如 username_1。并检查该用户名是否存在,如果存在,则再次将其增加到 username_2 直到创建新用户名。我已经创建了这个函数,但它没有返回任何内容。请帮助我解决我的代码中的问题。
class a{
function check_username($username){
if($usernameexist){
return true;
}
else
{
return false;
}
}
function create_username($username) {
$__name = __FUNCTION__;
if ($this->check_username($username)) {
$n++;
$username = $username . "_" . $n;
//return $__name($username); this return fatal error.
return call_user_func('create_username', $username);
} else {
return $username;
}
}
}
最佳答案
无需为此使用递归,一个简单的 while(){}
循环即可:
简单的交互器方法
// your original function
function create_username($username){
// check if the username (as-is) already exists
if ($this->check_username($username)){
// use $n to keep a counter
$n = 1;
// while {username}_{n} exists, keep incrementing the counter
while ($this->check_username($username.'_'.$n)){
$n++;
/* If you don't want this to check to infinity, uncomment
* the below portion. the 100 is an arbitrary number, but use
* whatever you want as a limitation (could even make it a
* parameter in the method). Also, returning FALSE allows you to
* gracefully catch when max attempts are reached.
*
* e.g.
* if (($new_user = $obj->create_username('BradChristie')) !== FALSE){
* // user was successfully created within the max allowed attempts
* }
*/
//if ($n > 100) return FALSE
}
// return the result
return $username.'_'.$n;
}
// username was fine, return it back
return $username;
}
递归方法
// recursive username check
public function create_username($username, $n = 0)
{
/* Same as above function, this is a check to prevent counting
* to infinity. uncomment to apply it
*/
//if ($n > 100) return FALSE;
// establish the username we're testing. if $n is 0,
// it's the original call to the function (don't add _0)
// if it's >0, it's part of the search so include it
$_username = $username . ($n > 0 ? '_'.$n : '');
// check if the username exists.
if ($this->check_username($_username))
{
// it exists, so make a call to this same function passing
// the original username and the value of n + 1 (move to next
// possibility)
return $this->create_username($username, $n+1);
}
// the name, as-is, was fine. return it
return $_username;
}
关于php - php类中的递归函数,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/14359431/