I am trying to build a function that will call another function.
For example, if I have an array full of function names to call, is it possible to call a function for every array value without writing it in a script?
Example:
function email($val=NULL) {
if($val)
$this->_email = $val;
else
return $this->_email;
}
function fname($val=NULL) {
if($val)
$this->_fname = $val;
else
return $this->_fname;
}
For email, fname, etc.
But I want to have it like:
function contr_val($key,$val) {
function $key($val=NULL) {
if($val)
$this->_$key = $val;
else
return $this->_$key;
}
function $key($val="hallo");
}
And call it with:
contr_val("email", "test")
You're really trying to create member variables dynamically and retrieve their values. This is what __get() and __set() are for.
Here's how you could use it:
class TestClass {
var $data = array();
public function __set($n, $v) { $this->data[$n] = $v; }
public function __get($n) {
return (isset($this->data[$n]) ? $this->data[$n] : null);
}
public function contr_val($k, $v = NULL) {
if ($v)
$this->$k = $v;
else
return $this->$k;
}
};
$sherp = new TestClass;
$sherp->contr_val("Herp", "Derp");
echo "Herp is: " . $sherp->contr_val("Herp") . "\n";
echo "Narp is: " . $sherp->contr_val("Narp") . "\n";
Something like this:
/*
Input: $val - any value
$varname - the variable name, for instance: _email
*/
function checkValue($val=NULL, $varname) {
if($val)
$this->$var = $val;
else
return $this->$var;
}
checkValue("hello", "_email");
checkValue("hello2", "_name");
If you are doing this for a class, consider using PHP's magic methods __get() and
__set().
In an array full of function names, this calls every function that exists.
ghoti#pc:~$ cat functest.php
#!/usr/local/bin/php
<?php
function one() { print "one\n"; }
function two() { print "two\n"; }
function three() { print "three\n"; }
$a=array( "one", "two", "three", "four" );
foreach ($a as $item) {
if (function_exists($item)) {
$item();
} else {
print "No such function: $item\n";
}
}
ghoti#pc:~$ ./functest.php
one
two
three
No such function: four
ghoti#pc:~$
You need to check if the function exists or not:
function contr_val($key,$val) {
if (!function_exists($key)) {
function $key($val=NULL) {
if ($val)
$this->_$key = $val;
}
}
else {
return $this->_$key;
}
}
Related
I'm trying to do something like this:
function get_value($value)
{
if (is_null($value)) {
if ($value expects array) {
return ['hello', 'world'];
}
else {
return 'hello world';
}
}
return $value;
}
So that I can call it in an echo or a foreach like this:
$value = null;
foreach(get_value($value) as $value) {
echo $value;
}
echo get_value($value);
So the foreach would expect an array, but the echo would expect a string.
Is this possible?
It is not possible to use functions like that.
However, if you go a bit further and start using objects then you can actually achieve that by creating a class that implements the IteratorAggregate interface together with defining the __toString() magic method.
class GetValue implements \IteratorAggregate
{
private $value;
public function __construct($value = null)
{
$this->value = $value === null ? ['hello', 'world'] : (array) $value;
}
public function getIterator() {
return new \ArrayIterator($this->value);
}
public function __toString()
{
return implode(' ', $this->value);
}
}
$valueIterator = new GetValue();
echo $valueIterator;
foreach ($valueIterator as $key => $value) {
echo "\n" . $key . ' => ' . $value;
}
Example on sandbox
I'm not particularly familiar with php, and I'm having trouble understanding what's happening. Using a condensed skeleton of what I have:
class Helper
{
public function __construct($value)
{
$this->value = $value;
//etc
}
private function prefix($val)
{
return '1234' . $val;
}
private function otherFunction()
{
$this->value->someFunction(function ($err, $result) {
if($err !== null) {
echo $err->getMessage();
}
return $result;
});
}
public function help()
{
echo $this->prefix('5678'); //outputs 12345678
echo is_null($this->otherFunction()); //outputs 1
}
}
Why does otherFunction return null? I can echo $result right before the return and see what I'm expecting, but it's null afterwards.
Your otherFunction() doesn't return anything. Probably you echo $result inside of the callback function passed to $this->value->someFunction().
Add return just before $this->value->someFunction(... to return the value from otherFunction().
I want to have a function and then use it multiple times with different parameters.
For example:
<?php
class Test {
var $test;
public function func($val) {
$this->test = $val;
}
public function buildFunc() {
if(!empty($this->test)) {
$ret = $this->test;
}
return $ret;
}
}
?>
Then on calling page:
$test = new Test;
$test->func("test1");
$test->func("test2");
echo $test->buildFunc();
Then it prints test2 on the screen. And I want it to print out both of them.
Either create 2 instances of your object;
$test1 = new Test;
$test1->func("test1");
$test2 = new Test;
$test2->func("test2");
echo $test1->buildFunc();
echo $test2->buildFunc();
Or make test an array;
class Test {
var $test = array();
public function func($val) {
$this->test[] = $val;
}
public function buildFunc() {
return print_r($this->test, true);
}
}
May be you mean that you want to store all values? Then use an array:
public function func($val) {
$this->test[] = $val;
}
public function buildFunc() {
return $this->test
}
And then work with the result as with an array.
Well.. your code does exactly what are you telling it to do. Consider situation when you have no OOP:
$str = 'test 1';
$str = 'test 2';
echo $str; //prints test 2
So you need to echo them separately as if it wont be an OOP situation.
$test = new Test;
$test->func("test1");
echo $test->buildFunc();
$test->func("test2");
echo $test->buildFunc();
When calling the method create 2 instances of the test object.
$test = new Test;
$test->func("test1");
echo $test->buildFunc();
$test2 = new Test;
$test2->func("test2");
echo $test2->buildFunc();
if you dont want to create 2 instances you have to make a array instead.
How about create a constructor and initialize the value of test and concat the second value.
<?php
class Test {
var $test;
public function __construct($init){
$this->test = $init;
}
public function func($val) {
$this->test .= $val;
return $this;
}
public function buildFunc() {
if(!empty($this->test)) {
$ret = $this->test;
}
return $ret;
}
}
$test = new Test("test1");
$test->func("test2");
echo $test->buildFunc();
?>
When you say both do you mean something like
test1test2
or do you want
test1
test2
For the first option you can just append the string:
<?php
class Test {
var $test;
public function func($val) {
$this->test = $test . $val; <-- add val to the end
}
public function buildFunc() {
if(!empty($this->test)) {
$ret = $this->test;
}
return $ret;
}
}
?>
For the second:
<?php
class Test {
var $test = array();
public function func($val) {
$this->test[] = $val; <-- add val to
}
public function buildFunc() {
if(!empty($this->test)) {
foreach($test as $item){
echo $item . "<br/>";
}
}
}
}
?>
Push the variables to an array
<?php
class Test {
var $test;
public function __construct(){
$this->test=array();//Declare $test as an array
}
public function func($val) {
$this->test[]=$val;//Push to array
}
public function buildFunc() {
if(!empty($this->test)) {
$ret = implode(",",$this->test);
}
return $ret;
}
}
?>
class example()
{
function shout($var)
{
echo 'shout'.$var;
}
function whisper($var, $bool)
{
if($bool)
{
echo $var;
}
}
}
$obj = new example();
if($var)
{
$func = $obj->shout();
}else
{
$func = $obj->whisper();
}
I want to prepare the function variable first for later use instead of putting conditions in a loop. Is there a possible way to do it?
You can call methods by name:
if ($var) {
$fn = 'shout';
} else {
$fn = 'whisper';
}
$obj->$fn();
You can put the function name in a string:
if($var)
{
$func = 'shout';
}else
{
$func = 'whisper';
}
Later on:
$obj->$func
You can also use a callback:
if($var)
{
$func = array($obj, 'shout');
}else
{
$func = array($obj, 'whisper');
}
Later:
call_user_func($func);
or:
call_user_func_array($func, $args);
This question already exists:
Closed 11 years ago.
Possible Duplicate:
Any way to access array directly after method call?
In C# and other languages, I can do something like this
$value = $obj->getArray()[0];
But not in PHP. Any workarounds or am I doomed to do this all the time?
$array = $obj->getArray();
$value = $array[0];
No, you can't do it without using array_shift (Which only gets the first element). If you want to access the third or fourth, most likely you'd want to do a function like this:
function elemnt($array, $element)
{
return $array[$element];
}
$value = element($obj->getArray(), 4);
Also, see this question, as it is an exact duplicate: Any way to access array directly after method call?
I think you are doomed to do it that way :(
You can do this:
$res = array_pop(array_slice(somefunc(1), $i, 1));
If this is a one-off or occasional thing where the situation in your example holds true, and you're retrieving the first element of the return array, you can use:
$value = array_shift($obj->getArray());
If this is a pervasive need and you often need to retrieve elements other than the first (or last, for which you can use array_pop()), then I'd arrange to have a utility function available like so:
function elementOf($array, $index = 0) {
return $array[$index];
}
$value = elementOf($obj->getArray());
$otherValue = elementOf($obj->getArray(), 2);
Well, maybe this could help you, in php spl, pretty usefull, you can make you a Special Array for you:
<?php
class OArray extends ArrayObject{
public function __set($name, $val) {
$this[$name] = $val;
}
public function __get($name) {
return $this[$name];
}
}
class O{
function __construct(){
$this->array = new OArray();
$this->array[] = 1;
$this->array[] = 2;
$this->array[] = 3;
$this->array[] = 4;
}
function getArray(){
return $this->array;
}
}
$o = new O();
var_dump( $o->getArray()->{1} );
<?php
class MyArray implements Iterator ,ArrayAccess
{
private $var = array();
//-- ArrayAccess
public function offsetSet($offset, $value) {
if (is_null($offset)) {
$this->var[] = $value;
} else {
$this->var[$offset] = $value;
}
}
public function offsetExists($offset) {
return isset($this->var[$offset]);
}
public function offsetUnset($offset) {
unset($this->var[$offset]);
}
public function offsetGet($offset) {
return isset($this->var[$offset]) ? $this->var[$offset] : null;
}//-- Iterator
public function __construct($array){
if (is_array($array)) {
$this->var = $array;
}
}
public function rewind() {
reset($this->var);
}
public function current() {
return current($this->var);
}
public function key() {
return key($this->var);
}
public function next() {
return next($this->var);
}
public function valid() {
return ($this->current() !== false);
}
}
$values = array(
"one" => 1,
"two" => 2,
"three" => 3,
);
$it = new MyArray($values);
foreach ($it as $a => $b) {
print "$a: $b<br>";
}
echo $it["one"]."<br>";?>