Why does `array_push` not return the array it modified? [closed]

Question

This question is unlikely to help any future visitors; it is only relevant to a small geographic area, a specific moment in time, or an extraordinarily narrow situation that is not generally applicable to the worldwide audience of the internet. For help making this question more broadly applicable, visit the help center.

Closed 12 years ago.

The community reviewed whether to reopen this question 12 months ago and left it closed:

Original close reason(s) were not resolved

I am facing a strange problem in array_push function of php.

Lets see my code:

$sets_collection=array();
foreach($result['ques'] as $val){
    $sets_collection=array_push($sets_collection,$val['set']);
}

It gives me the error:

Message: array_push() expects parameter 1 to be array, integer given

But when I do this, it works fine:

$sets_collection=array();
$i=0;
foreach($result['ques'] as $val)
{
    $sets_collection[$i]=$val['set']; 
    $i++;
}

Why does this happen? Is it necessary that there should be a index of an array than we can perform the push operation? Because in my first case the array $set_collection does not have an index.

RTFM for array_push, see its return value and read the examples. — deceze
– deceze ♦, Commented Nov 19, 2012 at 13:33
syntax error ! $sets_collection[]=$val['set'] is same as array_push($sets_collection,$val['set']) ,and array_push returns new array count. After 1st iteration you will see the error in case 1. — sakhunzai
– sakhunzai, Commented Nov 19, 2012 at 13:42

Ja͢ck · Accepted Answer · 2012-11-19 13:34:25Z

2

Try this

$sets_collection=array();

foreach($result['ques'] as $val){
    array_push($sets_collection,$val['set']); 
}

edited Nov 19, 2012 at 13:34

Ja͢ck

174k39 gold badges269 silver badges316 bronze badges

answered Nov 19, 2012 at 13:32

som

4,6542 gold badges23 silver badges36 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

Harshal Over a year ago

i tried same in my 1st case ,this gave me error.

Harshal Over a year ago

No i got now my mistake,this works fine...Thanks:(

mickmackusa Dec 6, 2024 at 19:36

Looks like a less elegant form of array_column().

Fad · Accepted Answer · 2012-11-19 13:34:02Z

2

That's because array_push() returns the new number of elements inside the array. You don't assign the returned value to the array variable. The first parameter is actually passed by reference. Thus, its value is mutated by the function.

answered Nov 19, 2012 at 13:34

Fad

9,8683 gold badges48 silver badges65 bronze badges

Comments

Ravi · Accepted Answer · 2012-11-19 13:36:07Z

2

This is because array_push returns new number of elements in the array, when you pushes the array in first iteration it works but in second iteration $sets_collection becomes 1 which is an integer so the function fails with the mentioned error.

Reference: array_push()

answered Nov 19, 2012 at 13:36

Ravi

2,08613 silver badges23 bronze badges

Comments

Akber Choudhry · Accepted Answer · 2012-11-19 13:57:57Z

0

array_push does not return an array - just an integer. Perhaps as the variable sets_collection is presumed to have changed to an integer because of the expected return of array_push, the subsequent parameter is also treated as an integer.

Just remove the assignment, and it should work fine.

array_push($sets_collection,$val['set']);

answered Nov 19, 2012 at 13:57

Akber Choudhry

1,79518 silver badges25 bronze badges

Collectives™ on Stack Overflow

Why does `array_push` not return the array it modified? [closed]

4 Answers 4

3 Comments

Comments

Comments

Comments

Linked

Hot Network Questions

Collectives™ on Stack Overflow

4 Answers 4

3 Comments

Comments

Comments

Comments

Linked

Related