我需要能够调用一个函数，但函数名存储在一个变量，这是可能的吗?例句:
function foo ()
{
//code here
}
function bar ()
{
//code here
}
$functionName = "foo";
// I need to call the function based on what is $functionName
当前回答
补充@Chris K的回答，如果你想调用一个对象的方法，你可以在闭包的帮助下使用一个变量来调用它:
function get_method($object, $method){
return function() use($object, $method){
$args = func_get_args();
return call_user_func_array(array($object, $method), $args);
};
}
class test{
function echo_this($text){
echo $text;
}
}
$test = new test();
$echo = get_method($test, 'echo_this');
$echo('Hello'); //Output is "Hello"
我在这里举了另一个例子
其他回答
补充@Chris K的回答，如果你想调用一个对象的方法，你可以在闭包的帮助下使用一个变量来调用它:
function get_method($object, $method){
return function() use($object, $method){
$args = func_get_args();
return call_user_func_array(array($object, $method), $args);
};
}
class test{
function echo_this($text){
echo $text;
}
}
$test = new test();
$echo = get_method($test, 'echo_this');
$echo('Hello'); //Output is "Hello"
我在这里举了另一个例子
我从这个问题和答案中学到了什么。感谢所有!
假设我有这些变量和函数:
$functionName1 = "sayHello";
$functionName2 = "sayHelloTo";
$functionName3 = "saySomethingTo";
$friend = "John";
$datas = array(
"something"=>"how are you?",
"to"=>"Sarah"
);
function sayHello()
{
echo "Hello!";
}
function sayHelloTo($to)
{
echo "Dear $to, hello!";
}
function saySomethingTo($something, $to)
{
echo "Dear $to, $something";
}
To call function without arguments // Calling sayHello() call_user_func($functionName1); Hello! To call function with 1 argument // Calling sayHelloTo("John") call_user_func($functionName2, $friend); Dear John, hello! To call function with 1 or more arguments This will be useful if you are dynamically calling your functions and each function have different number of arguments. This is my case that I have been looking for (and solved). call_user_func_array is the key // You can add your arguments // 1. statically by hard-code, $arguments[0] = "how are you?"; // my $something $arguments[1] = "Sarah"; // my $to // 2. OR dynamically using foreach $arguments = NULL; foreach($datas as $data) { $arguments[] = $data; } // Calling saySomethingTo("how are you?", "Sarah") call_user_func_array($functionName3, $arguments); Dear Sarah, how are you?
耶再见！
我最喜欢的版本是内联版本:
${"variableName"} = 12;
$className->{"propertyName"};
$className->{"methodName"}();
StaticClass::${"propertyName"};
StaticClass::{"methodName"}();
你也可以把变量或表达式放在括号里!
是的，这是可能的:
function foo($msg) {
echo $msg."<br />";
}
$var1 = "foo";
$var1("testing 1,2,3");
来源:http://www.onlamp.com/pub/a/php/2001/05/17/php_foundations.html?page=2
动态函数名和命名空间
只是在使用名称空间时补充一点关于动态函数名的内容。
如果你正在使用命名空间，下面的代码将不起作用，除非你的函数在全局命名空间中:
namespace greetings;
function hello()
{
// do something
}
$myvar = "hello";
$myvar(); // interpreted as "\hello();"
怎么办呢?
你必须使用call_user_func()来代替:
// if hello() is in the current namespace
call_user_func(__NAMESPACE__.'\\'.$myvar);
// if hello() is in another namespace
call_user_func('mynamespace\\'.$myvar);
