CODEWITHSUNDEEP
phpcodeigniter-2
user1284897
user1284897

Reputation: 3

php codeigniter - var_dump shows array but return is null

so, this is weird, I have this method called treetrunk that runs up a parent child relationship and is supposed to return an array if ids as a "branchPath" - the method seems to be working just fine as a var_dump in my terminating condition shows the proper array. However if i try to call the method the returned array is "NULL" - I really dont get it..

Model method:

function treeTrunk($id){//1st id in is page id
    if($id == '0'){
        var_dump($this->branchPath); //this shows perfect array 
        return $this->branchPath; //this returns null
    }
    else{
        $q = $this->getWhere(array('id'=>$id),null,null);
        array_push($this->branchPath, $q[0]['pageParent']);
        $this->treeTrunk($q[0]['pageParent']);
    }       
}

Calling via controller:

$d = $this->pages_mdl->treeTrunk('150');
var_dump($d); // <- this == NULL

var_dump from within method outputs "array(3) { [0]=> string(3) "148" [1]=> string(3) "146" [2]=> string(1) "0" } "

Upvotes: 0

Views: 1935

Answers (2)

Hanky Panky
Hanky Panky

Reputation: 46900

That is supposed to be NULL

else{
    $q = $this->getWhere(array('id'=>$id),null,null);
    array_push($this->branchPath, $q[0]['pageParent']);
    $this->treeTrunk($q[0]['pageParent']);  // You have to return this value as well
}

When you don't return that array, what else do you expect it to send back ? add a return statement there. When you are dealing with recursion then your last call returned the value to your second last call, but did that call return it back to the original caller? so add a return there

   return $this->treeTrunk($q[0]['pageParent']);

And also remove the quotation marks around integer values, not only does it look bad, it sometimes stops working as expected in PHP then.

Demo

Upvotes: 0

Yogesh Suthar
Yogesh Suthar

Reputation: 30488

You are not returning anything in else part.

else{
    $q = $this->getWhere(array('id'=>$id),null,null);
    array_push($this->branchPath, $q[0]['pageParent']);
    $this->treeTrunk($q[0]['pageParent']);
}

should be

else{
    $q = $this->getWhere(array('id'=>$id),null,null);
    array_push($this->branchPath, $q[0]['pageParent']);
    return $this->treeTrunk($q[0]['pageParent']);
}

As posted in you question you are passing 150 to treeTrunk() function, so it goes to else part and gives you null result. The if part will evaluate when you pass 0 to treeTrunk() function.

Upvotes: 1

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