I am playing around with this:
$sort = array('t1','t2');
function test($e){
echo array_search($e,$sort);
}
test('t1');
and get this error:
Warning: array_search(): Wrong datatype for second argument on line 4
if I call it without function like this, I got the result 0;
echo array_search('t1',$sort);
What goes wrong here?? thanks for help.
Variables in PHP have function scope. The variable $sort is not available in your function test, because you have not passed it in. You'll have to pass it into the function as a parameter as well, or define it inside the function.
You can also use the global keyword, but it is really not recommended. Pass data explictly.
You must pass the array as a parameter! Because the functions variables are different from globals in php!
Here is the fixed one:
$sort = array('t1','t2');
function test($e,$sort){
echo array_search($e,$sort);
}
test('t2',$sort);
You cannot directly access global variables from inside functions.
You have three options:
function test($e) {
global $sort;
echo array_search($e, $sort);
}
function test($e) {
echo array_search($e, $GLOBALS['sort']);
}
function test($e, $sort) {
echo array_search($e, $sort);
} // call with test('t1', $sort);
take the $sort inside the function or pass $sort as parameter to function test()..
For e.g.
function test($e){
$sort = array('t1','t2');
echo array_search($e,$sort);
}
test('t1');
----- OR -----
$sort = array('t1','t2');
function test($e,$sort){
echo array_search($e,$sort);
}
test('t1',$sort);
Related
In codeigniter what is the correct method of passing variables to the callback function?
I have used this,
$var1 = 'some conditions';
$this->form_validation->set_rules("callback__is_value_unique[value, $var1]");
public function _is_value_unique($value, $var1){
echo $var1;
die;
}
This gave me output like shown below:-
value, some conditions
rather than,
some conditions
You must only set your value!
$var1 = 'some conditions';
$this->form_validation->set_rules("callback__is_value_unique[value, $var1]");
public function _is_value_unique($value, $var1){
echo $var1;
die;
}
From the docs..
If you need to receive an extra parameter in your callback function,
just add it normally after the function name between square brackets,
as in: "callback_foo[bar]", then it will be passed as the second
argument of your callback function.
Sounds like you could only pass one extra argument. Which should be a string. If you want to pass more arguments, you could store them somewhere else and just pass an argument, which stores the location of the additional param.
$index = count($this->arguments);
$this->arguments[$index] = array('value', 'some conditions'/*, ...*/);
$this->form_validation->set_rules("callback__is_value_unique[$index]");
public function _is_value_unique($value, $index){
$args = $this->argumts[$index];
echo $args[1];
die;
}
I have a function variable like this...
$aName = "My Name";
The function need to pass in like this:
$sayHelloFunction = function sayHello($aName){
echo($aName);
}
Than, I have a method that responsible for execute the sayHelloFunction:
runningFunction($sayHelloFunction($aName));
in the runningFunction, it will have some condition to execute the function, but when I pass the "$sayHelloFunction($aName)" to runningFunction, it execute automatically, but I would like to pass the variable $aName as well, how can I achieve it? Thank you.
runningFunction($sayHelloFunction, $aName);
Simples.
You will have to pass the arguments separately. However, you could wrap them in an array so that you can pass them to runningFunction as a single argument, like this:
$printFunction = function($args) {
print $args['lastname'].', '.$args['firstname'];
};
function runningFunction($f, $a) {
$f($a);
}
$firstname = 'Bob';
$lastname = 'Smith';
$functionArguments = array(
'firstname' => $firstname,
'lastname' => $lastname
);
runningFunction($printFunction, $functionArguments);
If you want your dynamic functions to get "proper" arguments, then I see no way around something like this:
function runningFunction($f, $a) {
switch(count($a)) {
0: $f(); break;
1: $f($a[0]); break;
2: $f($a[0], $a[1]); break;
3: $f($a[0], $a[1], $a[2]); break;
// and so on
}
}
Pass the parameters as an array, and then use call_user_func_array() to call your function.
This way your runningFunction() will be absolutely abstract (as you requested), it can call any type of function, it's your responsibility to pass the right number of parameters.
function runningFunction ($callback, $parameters=array()) {
call_user_func_array($callback, $parameters);
}
runningFunction($sayHelloFunction, array($aName));
call_user_func_array()
as xconspirisist suggested pass $aName as a seperate parameter to the function.
Details on Variable Functions can be found on the PHP site.
Use an anonymous function when calling runningFunction
function runningFunction($func) {
$func();
}
runningFunction(function() {
$sayHelloFunction($aName));
// You can do more function calls here...
});
I have a function to send mail to users and I want to pass one of its parameter as an array of ids.
Is this possible to do? If yes, how can it be done?
Suppose we have a function as:
function sendemail($id, $userid) {
}
In the example, $id should be an array.
You can pass an array as an argument. It is copied by value (or COW'd, which essentially means the same to you), so you can array_pop() (and similar) all you like on it and won't affect anything outside.
function sendemail($id, $userid){
// ...
}
sendemail(array('a', 'b', 'c'), 10);
You can in fact only accept an array there by placing its type in the function's argument signature...
function sendemail(array $id, $userid){
// ...
}
You can also call the function with its arguments as an array...
call_user_func_array('sendemail', array('argument1', 'argument2'));
even more cool, you can pass a variable count of parameters to a function like this:
function sendmail(...$users){
foreach($users as $user){
}
}
sendmail('user1','user2','user3');
Yes, you can safely pass an array as a parameter.
Yes, you can do that.
function sendemail($id_list,$userid){
foreach($id_list as $id) {
printf("$id\n"); // Will run twice, once outputting id1, then id2
}
}
$idl = Array("id1", "id2");
$uid = "userID";
sendemail($idl, $uid);
What should be clarified here.
Just pass the array when you call this function.
function sendemail($id,$userid){
Some Process....
}
$id=array(1,2);
sendmail($id,$userid);
function sendemail(Array $id,$userid){ // forces $id must be an array
Some Process....
}
$ids = array(121,122,123);
sendmail($ids, $userId);
Its no different to any other variable, e.g.
function sendemail($id,$userid){
echo $arr["foo"];
}
$arr = array("foo" => "bar");
sendemail($arr, $userid);
I composed this code as an example. Hope the idea works!
<?php
$friends = array('Robert', 'Louis', 'Ferdinand');
function greetings($friends){
echo "Greetings, $friends <br>";
}
foreach ($friends as $friend) {
greetings($friend);
}
?>
I found Delcon answer helpful but I was looking for this
function sendmail($user1, $user2, $user3){
echo $user1;
echo $user2;
echo $user3;
}
$users = array('user1','user2','user3');
sendmail(...$users);
In php 5, you can also hint the type of the passed variable:
function sendemail(array $id, $userid){
//function body
}
See type hinting.
Since PHP is dynamically weakly typed, you can pass any variable to the function and the function will try to do its best with it.
Therefore, you can indeed pass arrays as parameters.
Yes, we can pass arrays to a function.
$arr = array(“a” => “first”, “b” => “second”, “c” => “third”);
function user_defined($item, $key)
{
echo $key.”-”.$item.”<br/>”;
}
array_walk($arr, ‘user_defined’);
We can find more array functions here
http://skillrow.com/array-functions-in-php-part1/
<?php
function takes_array($input)
{
echo "$input[0] + $input[1] = ", $input[0]+$input[1];
}
?>
i've been coding asp and was wondering if this is possible in php:
$data = getData($isEOF);
function getData($isEOF=false)
{
// fetching data
$isEOF = true;
return $data;
}
the function getData will return some data, but i'd like to know - is it possible to also set the $isEOF variable inside the function so that it can be accessed from outside the function?
thanks
It is possible, if your function expects it to be passed by reference :
function getData(& $isEOF=false) {
}
Note the & before the variable's name, in the parameters list of the function.
For more informations, here's the relevant section of the PHP manual : Making arguments be passed by reference
And, for a quick demonstration, consider the following portion of code :
$value = 'hello';
echo "Initial value : $value<br />";
test($value);
echo "New value : $value<br />";
function test(& $param) {
$param = 'plop';
}
Which will display the following result :
Initial value : hello
New value : plop
Using the global statement you can use variables in any scope.
$data = getData();
function getData()
{
global $isEOF;
// fetching data
$isEOF = true;
return $data;
}
See http://php.net/manual/en/language.variables.scope.php for more info.
Yes, you need to pass the variable by reference.
See the example here : http://www.phpbuilder.com/manual/functions.arguments.php
How to write a php function in order to pass parameters
like this
student('name=Nick&roll=1234');
If your format is URL encoded you can use parse_str to get the variables in your functions scope:
function student($args)
{
parse_str($args);
echo $name;
echo $roll;
}
Although, if this string is the scripts URL parameters you can just use the $_GET global variable.
Pass parameters like this:
student($parameter1, $parameter2){
//do stuff
return $something;
}
call function like this:
student($_GET['name'], $_GET['roll']);
Use parse_str.
function foo($paraString){
try{
$expressions = explode('&',$paraString);
$args = array();
foreach($expressions as $exoression){
$kvPair = explode('=',$exoression);
if(count($kvPair !=2))throw new Exception("format exception....");
$args[$kvPair[0]] = $kvPair[1];
}
....
Edit: that wayyou can do it manually. If you just want to get something out of a querrystring there are already functions to get the job done