PHP - "Sal's mall is $emo" vs "Sal's mall is ".$emo - string with quotes concatenation efficiency

Question

In PHP, which is a better way to concatenate strings (with a single-quote) in terms of resources?

"Sal's mall is $emo."

Or:

"Sal's mall is ".$emo.'.'

Or:

'Sal\'s mall is '.$emo.'.'

Answer 1

'Sal\'s mall is '.$emo.'.'

The third way is more efficient (slightly). You can test it by yourself doing a loop:

for ($i = 0; $i < 100000; $i++) {
    // enter code here 
}