很简单，但是似乎对if语句有麻烦

Question

I have this class of code and one piece of code just stops the whole thing from working and i am unable to figure out why.

Scenario: The method will send a json as a reply when called via ajax, the code works fine except for the if condition.

  if(false) // this stops the script { $menu[] = new jsTreeNode('node','nodeid'); } $menu[] = new jsTreeNode('node'); 

Actual if condition is a comparision of two values and not just false, if i put true or when the actual condition is true it works fine but false just stops the whole script. Any ideas??

Edit:

public function __construct($title, $nodeID = NULL)
{
    $this->data = new stdClass();
    $this->data->title = $title;
    $this->data->icon = 'assets/img/icons/'.strtolower($title).'.png';
    $this->attr = new stdClass();
    $this->attr->id = ($nodeID == NULL) ? strtolower($title) : strtolower($nodeID);

}

public function addChild($title, $nodeID = NULL)
{
    $this->children[] = new jsTreeNode($title, $nodeID);    
}

error_reporting throws no error.

Answer 1

Edit: after looking at your code you should always use the build in function of php to test values like null.

Try this:

$menu[] = (is_null($condition))? new jsTreeNode('node','nodeid') : new jsTreeNode('node');

Answer 2

This is from the php manual: http://php.net/manual/en/control-structures.if.php

If expression evaluates to TRUE, PHP will execute statement, and if it evaluates to FALSE - it'll ignore it.

Your expression by design evaluates to false and so PHP ignores it.

My guess is that using something like if(!true) would work better because if the condition you are giving the if statement is false, then the if statement would evaluate it as true.

Answer 3

Thanks to everyone who tried to help me out but i figured the problem out it seems there is an addchild call going to the $menu[] of agent node which was causing the bug. So when it was false the if condition worked fine but due to the missing agent node the script just stopped loading. Since it was an ajax call i only figured it out now. Thanks all the same to everyone!