PHP warning @foreach

Question

I have PHP foreach from an array, the array is provided to me by the database provider through a soapy web service, so I cannot modify the resulting array. When there are no items to return, I get an empty array, this leads to

Warning: Invalid argument supplied for foreach() 

the cycle looks like

 foreach (($point1['return']) as $val) 

Where can I put @ to stop this warning, and if I cannot, what am I doing, I am doing it to disable php warnings.

Answer 1

Hiding the warning is the wrong way. You should check if it exists and is an array.

 if (is_array($point1['return'])) { foreach ($point1['return'] as $val) { ... } } 

PHP is_array ()

In fact, turning off alerts or using the @ operator is the wrong way to jump in 99% of cases.

Solve the problem, not hide it.

Answer 2

An empty array does not cause this error, the problem is that you are trying to iterate through something that is not an array. You can add validation using is_array .

Answer 3

foreach () can process not only arrays , but also objects by using the default implementation of "all visible properties" or a custom implementation using traversable / iterator .
And “a database provider through a soapy web service” is that I will monitor the possibility of (suddenly) having an object / iterator instead of a simple array.
So, if you are going to check the existence and data type before passing the variable to foreach, you should consider not only testing is_array() but also for instanceof Traversable .

 <?php class Foo implements Iterator { protected $v = 0; public function current() { return $this->v; } public function key() { return $this->v; } public function next() { ++$this->v; } public function rewind() { $this->v=0; } public function valid() { return 10>$this->v; } } //$a = array(1,2,3,4); $a = new Foo; if( is_array($a) || $a instanceof Traversable ) { foreach($a as $e) { echo $e, "\n"; } } 

Answer 4

Check the array first:

 if(is_array($point1['return'])) { ... } 

Answer 5

It is better to allow errors to be displayed, but first check that the input is an array. This way you can wrap foreach in if, for example:

 if ((is_array($point1)) && (is_array($point1['return']))) { foreach (($point1['return']) as $val) ... } 

Answer 6

You can also explicitly pass an argument to an array:

 foreach ((array) $point1['return'] as $val) { 

Note: this will still produce an undefined index if in $point1

no key "return",

Answer 7

Check if this is an array. with is_array(); !! There is no need to suppress the warning. In fact, it is impossible to prevent this warning about an invalid argument.