Viewed   273 times

Something that really would like to know but never found out are shortcuts in PHP.

I am currently coding a function with a foreach loop with just a single statement inside. I tried to omit the curly braces as you can do in if/else control structures and it works. No errors.

foreach($var as $value)
    $arr[] = $value;

Now I tried to use it the same way but putting an if/else block inside it. Again, working and no errors.

foreach($var as $value)
    if(1 + 1 == 2) {
        $arr[] = $value;

Then, I thought like "why is this working?" and omitted the closing semicolon. Still working. So I tried to use the if/else statement without curly braces inside the foreach loop and again, still working and no errors. But is the foreach loop really closed/ended right now?

foreach($var as $value)
    if(1 + 1 == 2)
        $arr[] = $value;

At least I omitted the closing semicolon again and (as expected) a parsing error occurred.

So my big question is: When can I omit the curly braces and in which structure/loop/function? I know that I can definitely do so in if and else. But what about while, for and foreach?

And yes, I know that it is not safe, smart, whatever to code without curly braces and there are shorthands like $condition ? true : false; and if: doSomething(); endif;, endfor; and endforeach;. I don't wanna learn about shorthands I just want to understand the conditions about when and where it is possible to omit the curly brackets.



When you omit the braces it will only treat the next statement as body of the condition.

if ($x) echo 'foo';

is the same as

if ($x) { echo 'foo'; }

but remember that

if ($x)
  echo 'foo';
  echo 'bar';

will always print "bar"

Internally it's the other way around: if will only look at the next expression, but PHP treats everything in {} as a single "grouped" expression.

Same for the other control statements (foreach, and so on)

Friday, September 2, 2022

access the single byte with that index {0} => first char (in non-utf8 string)

you could simply test it with:

echo $var{0};
Tuesday, September 27, 2022

You should not be doing this dynamically in PHP, since PHP has no concept of the size of the screen (without help from client side cookies or something similar).

You should use a CSS media query for this. For example:

@media screen and (max-width: 1024px) {
  /* CSS for up to 1024px width */   

@media screen and (min-width: 1025px) {
  /* CSS for over 1024px width */

You can also use javascript to modify the CSS properties of an element. In fact your example seems to try to use jQuery syntax in PHP, which of course won't work.

Monday, August 29, 2022

The problem with the first version is that if you go back and add a second statement to the if or else clauses without remembering to add the curly braces, your code will break in unexpected and amusing ways.

Maintainability-wise, it's always smarter to use the second form.

EDIT: Ned points this out in the comments, but it's worth linking to here, too, I think. This is not just some ivory-tower hypothetical bullshit:

Saturday, September 10, 2022

if is not a loop structure, so you cannot "break out of it".

You can, however, break out of the foreach by simply calling break. In your example it has the desired effect:

$device = "wanted";
foreach($equipxml as $equip) {
    $current_device = $equip->xpath("name");
    if ( $current_device[0] == $device ) {
        // found a match in the file            
        $nodeid = $equip->id;

        // will leave the foreach loop and also the if statement
        some_function(); // never reached!
    another_function();  // not executed after match/break

Just for completeness for others that stumble upon this question looking for an answer..

break takes an optional argument, which defines how many loop structures it should break. Example:

foreach (array('1','2','3') as $a) {
    echo "$a ";
    foreach (array('3','2','1') as $b) {
        echo "$b ";
        if ($a == $b) { 
            break 2;  // this will break both foreach loops
    echo ". ";  // never reached!
echo "!";

Resulting output:

1 3 2 1 !

Saturday, December 24, 2022
Only authorized users can answer the search term. Please sign in first, or register a free account.
Not the answer you're looking for? Browse other questions tagged :