PHP如果条件号发出[重复]

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The php code is returing true in both cases show below. I dont know why?

<?php

$cid = 150;

if ($cid=100)
{
echo $cid;
echo "<BR>";
}

if ($cid==100)
{
echo "NEW";
echo "<BR>";
echo $cid;
echo "<BR>";
}

?>

The output is:
100
NEW
100


Why is the if condition not working?

</div>

In the first if-statement you are assigning 100 to $cid, not comparing. You're using a single = instead of ==. So in the first statement $cid is set to 100. When it comes to the second if-statement, $cid has a value of 100. So the conditional evaluates in a truthy value.