Correct PHP syntax for nested if else statements

[Relaxasaurus]

Hi guys,

I want to create an if else statement within an echo like this:

<? if (condition) == "blah") {
echo "Hello there " *insert nested if else statement here* ", welcome to our web site!";
} else {
echo "Please login.";
}

Actual code:

<div id="nav">
<ul>
	<? if ($thisSection == "Home") {
		echo "<li>You are home, browse sub-navigation below</li>
			<div id=\"subnav\">
				<ul>"
				if ($thisSubsection == 'Aboutus') { 
					echo '<li><img src='images/about_active.gif'></li>';
					} else { 
					echo '<li><img src='images/about.gif'></li>'; }
				if ($thisSubsection == 'History') { 
					echo '<li><img src='images/history_active.gif'></li>';
					} else { 
					echo '<li><img src='images/history.gif'></li>'; }
				"</ul>  //this line and the next are ignored
			</div>";
		
		} else {
		echo "You are not home";
		}
	?>
</ul>
</div>

I guess I want to add an if else statement within an echo, then continue the echo by closing the <ul> and <div> tags at the end, but I'm having problems continuing the echo after the nested if else statements. Is my syntax off?

[GJay]

It's much easier to use separate echos:

PHP Code:

<?php
if ($thisSection == "Home") {
  echo "<li>You are home, browse sub-navigation below</li>
  <div id=\"subnav\">
  <ul>";
  if ($thisSubsection == 'Aboutus') { 
    echo '<li><img src='images/about_active.gif'></li>';
  } else { 
    echo '<li><img src='images/about.gif'></li>'; 
  }
  if ($thisSubsection == 'History') { 
    echo '<li><img src='images/history_active.gif'></li>';
  } else { 
    echo '<li><img src='images/history.gif'></li>'; 
  }
  echo "</ul></div>";

} else {
  echo "You are not home";
}
?>

[Relaxasaurus]

thanks mayne, works like a charm!

[maltrecho]

You could also use ternary operators:
(it looks cleaner a nicer in this cases from my point of view)

PHP Code:

<?php

// condition ? true : false;

if ($thisSection == "Home") {

  echo "<li>You are home, browse sub-navigation below</li>
        <div id=\"subnav\">
        <ul>
        <li><img src=\"images/".(($thisSubsection == 'Aboutus') ? 'about_active.gif' : 'about.gif')."\"></li>
        <li><img src=\"images/".(($thisSubsection == 'History') ? 'history_active.gif' : 'history.gif')."\"></li>
        </ul>
        </div>";

} else {

  echo "You are not home";
}

?>

[BaDgEr]

I was going to suggest the same as Maltrecho.

[fail]

I have the same question and don't get it. This seems not to work as I wanted it to work:

PHP Code:

if (condition) 

{ statement }

ELSE {

if (condition) 

   {
   statement
   }

ELSE {
if (condition) 

{
statement
}

ELSE {

statement

}  // else 3
}  // else 2
}  // else 1 


What is the correct way to write it?

[tomharto]

PHP Code:

$a = 0;
if ($a == "1") {
    echo "A is 1";
}
else {
    if ($a == "2") {
        echo "A is 2";
    }
    else {
        if ($a == "3") {
            echo "A is 3";
        }
        else {
            echo "A isnt 1,2 or 3";
        }  // else 3
    }  // else 2
}  // else 1 


How about that? Or you could use elseif

PHP Code:

$a = 0;
if ($a == "1") {
    echo "A is 1";
}
elseif ($a == "2") {
     echo "A is 2";
}
elseif ($a == "3") {
    echo "A is 3";
}
else {
     echo "A isnt 1,2 or 3";
}  // else 1 


[fail]

I will need to test that.

I need it coz I check a text for keywords. If the first search-word is NOT found (and only then) I check for the next one. I have 3 words I am checking.

[tomharto]

If your check if one variable for 3 words you could use || (or) like this

PHP Code:

$a = 0;
if (($a == "1") || ($a == "2") || ($a == "3")) {
    echo "A matches the words";
else {
     echo "A doesnt match the word";
}  // else 1 


I dunno if that's better for what you need

[tangoforce]

I'd personally use a switch instead.

[tomharto]

Could you post a quick example of a switch? I'd like to have a look at it too

[Fou-Lu]

Originally Posted by tomharto

Could you post a quick example of a switch? I'd like to have a look at it too

PHP Code:

$a = 4;
switch ($a)
{
    case 1:
        print '1';
        break;
    case 2:
    case 3:
    case 4:
        print '> 1';
        break;
    default:
        print 'Unknown.';
} 


[tomharto]

Thanks . Now its time to figure out how that works :P

[tangoforce]

The switch can have any sort of different case statement. It's a very useful tool:

PHP Code:

switch ($Var)
   {
   case true://Boolean
      //Do something
      break;
   case is_numeric()://Function which returns true
      //Do something
      break;
   case 'string'://A string
      //Do something
      break;
   case 5://Integer
      //Do something
      break;
   default://Default for anything not matched by a case
      //Do something
      break;
   } 


Note that default is optional, and several cases can be grouped together as Fou-Lou has shown with 2,3 & 4. If you don't use break at the end of a cases code block then the switch will continue to execute after that block of code. In this case after the case for is_numeric() had run, if there was no break then the case for 5 would have also run.

[Fou-Lu]

The switch won't work properly with a function call, unless that function call is non-parametrized (and then will not relate directly to the switched value). For that you need to continue using an if/else handle so that you can give it the variable (this is honestly pointless):

PHP Code:

switch ($a)
{
    case is_numeric($a):
         print '$a is numeric';
         break;
} 


While it will work, its easier to just write if (is_numeric($a)).

Logically the switch works on the value of a variable, not directly on it. Thats why we specify it for the case. PHP (unlike most languages) will actually allow strings in its switch statements.
Also note that switches are loose in comparison.

PHP Code:

$a = 4;
switch ($a)
{
    case "4":
        print '$a is 4';
        break;
} 


That will print that $a is 4.

Edit:
I should clarify as well, I consider the loose comparison to be a negative.