为什么1没有被输出？ （简单的php问题）

Question

I have a question which I don't know the answer of. I've been thinking about it for a while.

The following code:

$i = 1;
while($i < 10) 
    if(($i++) % 2 == 0)
    echo $i;

It correctly outputs 3579, but why isnt 1 also included in the output?

I'm a beginner with PHP and am looking forward for someone to help me.

Thank you very much! :D

Answer 1

Two modifications:

$i = 0; // Make it 0 from 1
while($i < 10)
if(($i++) % 2 == 0)
echo "<br/>".$i; // Make $i instead of $1

Output:


1
3
5
7
9

Program hand run:

1) Set $i to 0.

2) If it is greater than 10, go ahead.

3) Increment it by 1

4) So, for $i => 0->1, 1->2

4) if new $i is even, print it. (So for first loop iteration, you are have $i -> 1 instead of 0 because of ++$i