The following code gives syntax error because of IF. How can I fix this without removing IF statement?
<?php
for ($i = 1; $i < 6; $i++){
$data .= 'h'.$i.'{'.
if ( !empty ($size) ) {.
'font-size: ' .$size. ';'.
}.
'}';
}
?>
Error:
Parse error: syntax error, unexpected 'if' (T_IF)
You cannot use an if statement within an expression, because it is syntactically wrong and the statement itself doesn't return a value. Use the ternary ?: operator which can be nested there:
$data .= 'h' . $i . '{' . (!empty($size) ? "font-size: $size" : '') . '}';
You could also benefit from the usage of double quotes to interpolate the variables instead of getting messy with the . operator.
You can't use if in string concatenation, but you can use shortcode:
for ($i = 1; $i < 6; $i++){
$data .= 'h'.$i.'{'.(!empty($size) ? ('font-size: ' .$size. ';') : '').'}';
}
I think it should be without error:
<?php
for ($i = 1; $i < 6; $i++){
$data .= 'h'.$i.'{' ;
if ( !empty ($size) ) {
$data .= 'font-size: ' .$size. ';';
}
$data .='}';
}
?>
for ($i = 1; $i < 6; $i++) {
$data .= "h$i{" . (!empty($size) ? "font-size: $size;" : "") . "}";
}
You can't string full-blown if's in-line, so either one of the following should fix this:
for ($i = 1; $i < 6; $i++)
{//ternary
$data .= 'h'.$i.'{'.( !empty ($size) ? 'font-size: ' .$size. ';' : '').'}';
}
Which is the same as writing:
for ($i = 1; $i < 6; $i++)
{
$data .= 'h'.$i.'{';
if (!empty ($size))
{
$data .= 'font-size: ' .$size. ';';
}
$data .= '}';
}
Well, to be 100% accurate, the ternary operator concats '' if $size is empty. The ternary syntax is as follows: [evaluate statement] ? [if true] : [else]. So the truly full-blown equivalent of that code is:
for ($i = 1; $i < 6; $i++)
{
$data .= 'h'.$i.'{';
if (!empty ($size))
{
$data .= 'font-size: ' .$size. ';';
}
else
{
$data .= '';
}
$data .= '}';
}
} should be outside if statementelse statement has no meaning.? [if true] : [else], when written in full, you wouldn't include the else, but ?: always needs a right side (else) statement, so transcribing the ternary in full leaves you with a pointless else statement, yes, but it's therefor ($i = 1; $i < 6; $i++){
$data .= 'h'.$i.'{'.((!empty ($size))?'font-size: {$size}':'').'}';
}
Explanation:
The following construct is called "ternary if":
$x = ($test == "Y")?"Yes!":"No!";
and is the same as:
if ($test == "Y"){
$x="Yes!";
} else {
$x="No!";
}
You are in the middle of adding stuff to a string in the line starting with $data.
Two solutions:
1) Stop adding stuff, start your if, add more stuff inside, stop if, then add the rest in a new statement.
$data .= 'h'.$i.'{';
if ( !empty ($size) ) {.
$data .= 'font-size: ' .$size. ';'.
}.
$data .= '}';
$data .= 'h'.$i.'{' (!empty($size) ? 'font-size: ' .$size. ';' : ''). '}';
The ternary operator evaluates the first argument to either true or false and returns the second or third argument, just like a function call.
Beware: Using ternary operators too much will make your code unreadable, especially when using it inside each other. You can always replace it with a separated IF construct like above for better readability. Plus the ternary operator cannot be easily extended to do more stuff besides returning one of two values.
