How come .=, =, =. are different?

BigBadKev

Hello,

sorry to be simple...but why does this not all mean the same expression? and is example 1 and 3 really the same? or is this a illusion.

Can someone also explain why example 2 fails if possible.

lets use below as the right hand side expression

$date = date("m/d/Y");

//example 1
$logdata .= "Date: $date\n";
//produces  Date: 07/01/2003 

//example 2
$logdata =. "Date: $date\n";
//fails......................

//example 3
$logdata = "Date: $date\n";
//produces Date: 07/01/2003

thanks in advance guys.

BBK
😃

sdjensen

= is assign
.= is concat

$date = date("m/d/Y"); 
$logdata = "XXX";

//example 1 
$logdata .= "Date: $date\n"; 
//produces  XXXDate: 07/01/2003 

//example 3 
$logdata = "Date: $date\n"; 
//produces Date: 07/01/2003

BigBadKev

Hi sdjensen and others,

Thanks for that, can you tel me why my example 2 fails?

BBK
😃

sdjensen

Because =. is not a valid function in php

What are you trying to do with the =. ?

BigBadKev

Hi sdjensen and others,

i was just playing around to see what works and it struck me as odd that the inverse of .= being =. would not work.

if i was to par-phrase in english I would say this.

.= means concat and equals "this object"

=. means equals "this object" and concat

This is why I found it odd that it didnt work.

BBK
😃

laserlight

$logdata =. "Date: $date\n";

means assign
. "Date: $date\n"
to $logdata

Since the period is not a recognizable constant here, it is invalid.

ereptur

I agree with you Kev. I wish there was a unary method of doing a string = string . string2. =. would be a decent way of doing that, but unfortunately, PHP (and no other language as far as I know) supports this type of unary assignment.

since you are playing around, I also suggest you mess around with == and ===.

ksandom

From what I known from other languages, I'm guessing that:
= assignment
== used in conditions
=== ummm ..... ummm

What is "==="? 😕