爆炸字符串并添加一个数字？ PHP

i'm realy done with this. My problem is the following:

code:

<?php
$highest = 0;
$string = "a.1";

$array = explode(".",$string);
$highest = $array[1];

$final = "secound value is: ".$highest++;

echo $final;
?>

All i want is adding something to the number in the $string. So as a result it should echo 2. However it echos 1.

Whats wrong?

Use pre-increment:

$final = "secound value is: ".++$highest;

More info: Incrementing/Decrementing Operators

Try the below code

<?php
$highest = 0;
$string = "a.1";

$array = explode(".",$string);
$highest = $array[1];

$final = "secound value is: ". ++$highest;

echo $final;
?>

The reason is, $highest++ is the post-increment. It will increment the value only after its usage. And ++$highest is pre-increment will increment the value first and then use it

You are doing a post increment. If you do a pre-increment, you will get 2 as your result. Is this what you want?

$final = "secound value is: ".++$highest;

Just to put an answer out of the box. You can save yourself exploding and an array that you may not need/want.

$highest = substr($str, 2) + 1;

There is a difference between pre-increment and post increment.

pre-increment-(++$highest)
   At first increase the value by one then executes the statement.
post-increment-($highest++)
   At first executes the statement then increase the value by one.

So in this case You have to use pre-increment.Then line will be executed after increment of the value .

Try this code:

<?php
$highest = 0;
$string = "a.1";

$array = explode(".",$string);
$highest = $array[1];

$final = "secound value is: ".++$highest;

echo $final;
?>