Increments

[Jigsaw]

Hi, im learning PHP atm and I'm very confused about how increments work and am failing to make sense of this example that was given to me:

e.g.

$a = 2; $b = $a++; // $a=3, $b=2

$a = 2; $b = ++$a; // $a=3, $b=3

So "$b" is simply in other terms "$a+1"?

And "$a" is 2, therefore $b is supposed to be 3 right? But it says its 2 instead?

Could explain how this works pls

 

[SRB]

This was wrote with C in mind, but language is irrelevant for this question.

http://stackoverflow.com/questions/24853/what-is-the-difference-between-i-and-i

Outside of reading then, play with a few example loops.

[Jigsaw]

Thanks for the reply.

I get the idea that ++i will increase the value of whatever "i" may be and then return/show the new value of "i"

and i++ will increase the value of "i" but still keep the original value...

Could you please provide me with an example where this might be used in mccodes (just to strengthen my understanding)?

[sniko]

I rarely come on here anymore...

 

<?php

$i = 1;         // Assign the value (int) 1 to the variable.
echo $i;        // Output the value of the variable.
echo PHP_EOL . PHP_EOL;

$i = 1;         // Assign the value (int) 1 to the variable.
echo $i + 1;    // Output the value of 1+1.
echo PHP_EOL . PHP_EOL;

$i = 1;         // Assign the value (int) 1 to the variable.
echo ++$i;      // Increment the variable by 1, then output.
echo PHP_EOL . PHP_EOL;

$i = 1;         // Assign the value (int) 1 to the variable.
echo $i++;      // Output the variable then increment by 1.

 

https://eval.in/708535

Notice how the last output is 1 (when I guess you expect it to be 2), this is because of where the operator (++) is. If you then output $i after this line, the output will be 2.

Edited January 3, 2017 by sniko