使用php打印星形图案时出现意外结果

Question

I am trying to print a star pattern using php. I am trying to print this:

    *
   **
  ***
 ****   
*****

my code:

for($i=1; $i<=5; $i++){
    for($j=1; $j<=5; $j++){
        if($j>= (6-$i)){
            echo "*";
        } else {
            echo " ";
        }

    }
    echo "<br>";
}

by doing this I should get above pattern but instead, I am getting this:

*
**
***
****
*****

Anybody can tell me why this is happening? Thanks in advance.

Answer 1

Extra whitespace characters in HTML documents have no effect on the rendered output. If you look at the output page source, you will see that you are getting the correct result. Here are your options:

1) Send a Content-Type: text/plain header:

header('Content-Type: text/plain');

Make sure to change your <br> tags to newline characters (" ", " ", or PHP_EOL)

2) Wrap what you have there with a <pre> tag

echo '<pre>';
for($i=1; $i<=5; $i++){
    for($j=1; $j<=5; $j++){
        if($j>= (6-$i)){
            echo "*";
        } else {
            echo " ";
        }

    }
    echo "<br>";
}
echo '</pre>';

3) Use non-breaking spaces:

for($i=1; $i<=5; $i++){
    for($j=1; $j<=5; $j++){
        if($j>= (6-$i)){
            echo "*";
        } else {
            echo "&nbsp;";
        }

    }
    echo "<br>";
}

On another note, here's a one-liner that will do the same thing as what you're trying to do without the additional for loop and if/else statements:

for ($i=1; $i<=5; $i++) {
    echo str_pad(str_repeat('*', $i), 5, ' ', STR_PAD_LEFT) . PHP_EOL;
}

Try it on 3v4l.org.