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Alberto Centelles
8,356 PointsI have this block of code that isn’t working correctly, but I can’t figure out the problem. It says that Cookie Dough an
Why does it display "Cookie Dough and Vanilla both start with C"?
<?php
$var1 = "Cookie Dough";
$var2 = "Vanilla";
$initial = "C";
if (stripos($var1,$initial) == 0 && stripos($var2,$initial) == 0) {
echo $var1 . " and " . $var2 . " both start with " . $initial . ".";
} else {
echo "Either " . $var1 . " or " . $var2 . " doesn't start with " . $initial . "; maybe neither of them do.";
}
?>
6 Answers
Jason Anello
Courses Plus Student 94,610 PointsHi Alberto,
The problem with the starter code is that it uses loose comparison == This means type juggling will occur in order to see if the two sides are equal.
stripos will return an index number if there's a match or FALSE if there's no match. 0 is considered a FALSE value so with a loose comparison you won't be able to tell the difference of whether 0 was returned or FALSE was returned.
if (stripos($var1,$initial) == 0 && stripos($var2,$initial) == 0) {
stripos($var1,$initial) is going to return 0 because a match is found at the beginning but stripos($var2,$initial) will FALSE because no match is found.
So you have:
if (0 == 0 && FALSE == 0) {
Both of these comparison are true because it's a loose comparison. Types will be converted in an attempt to get them equal.
You want to use the identity comparison ===
Now you have:
if (0 === 0 && FALSE === 0) {
Here the right comparison will be FALSE because they are not strictly equal. They have to match in both value and type. So the else block will be correctly executed.
You always want to use === with stripos() because otherwise, you can't tell the difference between a match at the beginning and no match at all.
Jeff Busch
19,287 PointsHi Alberto,
Change one of the zeros in the if statement to 1 or anything but zero.
Jeff
<?php
if (stripos($var1,$initial) == 0 && stripos($var2,$initial) == 1) {
?>
Alberto Centelles
8,356 PointsThanks Jeff! But, why is that? Why can't it be 0?
Jeff Busch
19,287 PointsHi Alberto,
I'm sorry, I wasn't thinking, the correct code is below.
Jeff
<?php
if (stripos($var1,$initial) == "C" && stripos($var2,$initial) == "C") {
?>
Alberto Centelles
8,356 PointsBut this function (stripos) gives you an integer or a boolean. It will give you a string, isn't it? The code worked, though
Jeff Busch
19,287 PointsI I did some searching around and the code below is correct, I believe. I don't fully understand why, but I will.
<?php
$var1 = "Cookie Dough";
$var2 = "Chocolate";
$initial = "C";
if (stripos($var1,$initial) === 0 && stripos($var2,$initial) === 0) {
echo $var1 . " and " . $var2 . " both start with " . $initial . ".";
} else {
echo "Either " . $var1 . " or " . $var2 . " doesn't start with " . $initial . "; maybe neither of them do.";
}
?>
Jeff Busch
19,287 PointsJeff Busch
19,287 PointsThere you have it. Give this guy twelve points Best Answer!
Jason Anello
Courses Plus Student 94,610 PointsJason Anello
Courses Plus Student 94,610 PointsThanks Jeff.
Travis Stewart
15,188 PointsTravis Stewart
15,188 PointsThanks. I was pretty hung up on this one.