Dynamically populate a subarray inside of an array declaration

Question

I'm trying to create an array inside an array, using a for loop - here's my code:

array(
 'label' => 'Assign to user',
 'desc' => 'Choose a user',
 'id' => $prefix . 'client',
 'type' => 'radio'
 'options' => array( 
 foreach ($clients as $user) {
 $user->user_login => array ( 
 'label' => $user->user_login, 
 'value' => $user->user_login,
 ), 
 }
 )
)

Unfortunately this gives me a

"Parse error: syntax error, unexpected T_CONSTANT_ENCAPSED_STRING, expecting ')'"

For the line:

'options' => array( 

I'm at a bit of a loss as to what has gone wrong. $clients is defined elsewhere, so that is not the problem.

Answer 1

That's invalid syntax. You'd have to build the "parent" portions of the array first. THEN add in the sub-array stuff with the foreach loop:

$foo = array(
 'label' => 'Assign to user',
 'desc' => 'Choose a user',
 'id' => $prefix.'client',
 'type' => 'radio',
 'options' => array()
);
foreach ($clients as $user) {
 $foo['options'][] = array ( 
 'label' => $user->user_login, 
 'value' => $user->user_login,
 );
}

• user319940: Unfortunately this doesn't seem to work for me as the array foo, is in an array itself which gives the error Parse error: syntax error, unexpected T_FOREACH, expecting ')'
• dhaupin: You don't need to make 'options' an array() if there is a chance it won't be filled. That may throw off some parsers to see an empty value (ie, schema json-ld).

Answer 2

You use foreach to access the data, not define it.

Try this:

array(
 'label' => 'Assign to user',
 'desc' => 'Choose a user',
 'id' => $prefix.'client',
 'type' => 'radio'
 'options' => $clients
 )

If you need to change the structure of the data for 'options', do this before defining the primary array.

• user319940: With this approach, how would I go about making $clients be an array of arrays? sorry if this sounds a little dense!
• ste: Define $clients first [code]$clients = array(array('oneval', 'two'), array('another', 'another'));[/code] then just include $clients in your primary array
• user319940: but I need to get the values by using a foreach loop as clients is used for a wordpress query: $clients = get_users()
• ste: Then make sure you've populated an array with the structure you expect and assign it to $clients - or try Marc's answer; same approach, different order
• user319940: Not quite sure what you mean by that, unfortunately Marc's code does not work in my situation (see comment), thanks for your help though.

Answer 3

You cannot use the foreach in the definition of the array. You can however put the $clients variable in the array itself or you can foreach outside the array to build the array to be inserted at the options key

Answer 4

array_map() will elegantly allow you to dynamically populate the subarray without needing to break out of tour original array. Demo

$result = [
 'label' => 'Assign to user',
 'desc' => 'Choose a user',
 'id' => $prefix . 'client',
 'type' => 'radio',
 'options' => array_map( 
 fn($user) => [ 
 'label' => $user->user_login, 
 'value' => $user->user_login,
 ], 
 $clients
 )
];