我的PHP for循环有什么问题？

Question

What's wrong with my PHP loop? It just loops until it eventually times out.

$max = 7;
$derp = $a / 5;
for($i = 1; $i < $max; $i++){
if($i = $derp){
echo"<option value='$derp' selected='selected'>$derp</option>";
}else{
echo"<option value='$i'>$i</option>";
}
}

Answer 1

Change

if($i = $derp){

to

if($i == $derp){

As you are currently assigning it, not comparing.

Answer 2

= is assignment. == is comparison.

Answer 3

if($i = $derp)应该是if($i == $derp)

Answer 4

= assigns a value to a variable. == compares for equality.

Answer 5

Try this:

$max = 7;
$derp = $a / 5;
for($i = 1; $i < $max; $i++){
if($i == $derp){
echo"<option value='$derp' selected='selected'>$derp</option>";
}else{
echo"<option value='$i'>$i</option>";
}
}

In your code you are trying to assign a $derp to $i .If you want to compare it change it as if($i == $derp) .