STRIP whitespaces and selected characters from the beginning of a STRING.
<?php
str ltrim ( str $str [, str $character_mask ] )
where,
$str = The input STRING
$character_mask = The list of additional characters
to strip from the beginning
?>
| DEFAULT | ASCII | VALUE | |
| " " | 32 | 0x20 | ESPAÇO |
| "\t" | 9 | 0x09 | TAB H |
| "\n" | 10 | 0x0A | NL |
| "\r" | 13 | 0x0D | CR |
| "\0" | 0 | 0x00 | NULL |
| "\x0B" | 11 | 0x0B | TAB V |
| ed48 | |||
EXERCISE
<?php
$strl01a = ' QUOSQUE TANDEM? ';
$strl01b = ltrim($strl01a);
echo $strl01b . '<br><br>';
$strl01c = ' QUOSQUE TANDEM? ';
$strl01d = ltrim($strl01c);
echo $strl01d;
?>
EXERCISE
<?php
$strl02a = '-/--//---///----QUOSQUE TANDEM?-/--//---///----';
$strl02b = ltrim($strl02a, '"-", "/"');
echo $strl02b . '<br><br>';
/* ---------------------------------------
list of characters defined by
a range of ASCII hexadecimal values
'0x29,..0x30' -> from 0x29 to 0x30
--------------------------------------- */
$strl02c = '-/--//---///----QUOSQUE TANDEM?-/--//---///----';
$strl02d = ltrim($strl02c, '0x29, ..0x30');
echo $strl02d;
?>
EXERCISE
<?php
echo "Testing ltrim() : basic functionality.<br>";
$text = " \t\r\n\0\x0B ---These are a few words--- ";
$hello = "!===Hello World===!";
$binary = "\x09\x0AExample string";
$alpha = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
echo "<br><br>Trim string with all white space characters:<br>";
var_dump(ltrim($text));
echo "<br><br>Trim non-whitespace from a string:<br>";
var_dump(ltrim($hello, "=!"));
echo "<br><br>Trim some non-white space
characters from a string:<br>";
var_dump(ltrim($hello, "!oleH="));
echo "<br><br>Trim some non-white space
characters from a string suing a character range:<br>";
var_dump(ltrim($alpha, "A..Z"));
echo "<br><br>Trim the ASCII control
characters at the beginning of a string:<br>";
var_dump(ltrim($binary, "\x00..\x1F"));
?>
EXERCISE
<?php
/* Testing for Error conditions */
/* Invalid Number of Arguments */
echo "<br><br>Output Conditions:<br>";
/* heredoc string */
$str = <<<EOD
us
ing heredoc string
EOD;
echo "<br><br>Using heredoc string:<br>";
var_dump( ltrim($str, "\nusi") );
/* Testing the Normal behaviour of ltrim() function */
echo "<br><br>Output for Normal Behaviour:<br>";
var_dump ( ltrim(" \t\0 ltrim test") );
/* without second Argument */
echo '<br><br>';
var_dump ( ltrim(" ltrim test" , "") );
/* no characters in second Argument */
echo '<br><br>';
var_dump ( ltrim(" ltrim test", NULL) );
/* with NULL as second Argument */
echo '<br><br>';
var_dump ( ltrim(" ltrim test", true) );
/* with boolean value as second Argument */
echo '<br><br>';
var_dump ( ltrim(" ltrim test", " ") );
/* with single space as second Argument */
echo '<br><br>';
var_dump ( ltrim("\t\n\r\0\x0B ltrim test", "\t\n\r\0\x0B") );
/* with multiple escape sequences as second Argument */
echo '<br><br>';
var_dump ( ltrim("ABCXYZltrim test", "A..Z") );
/* with characters range as second Argument */
echo '<br><br>';
var_dump ( ltrim("0123456789ltrim test", "0..9") );
/* with numbers range as second Argument */
echo '<br><br>';
var_dump ( ltrim("@$#ltrim test", "#@$") );
/* with some special characters as second Argument */
echo "<br><br>Output for scalar argument):<br>";
var_dump( ltrim( 12345 ) );
/* Scalar argument */
echo "<br><br>Output for NULL argument):<br>";
var_dump( ltrim(NULL) );
/* NULL Argument */
?>
EXERCISE
<?php
echo "Testing ltrim() : error conditions.<br>";
$hello = " Hello World\n";
echo "<br><br>Test ltrim function with
various invalid charlists:<br>";
var_dump(ltrim($hello, "..a"));
echo '<br><br>';
var_dump(ltrim($hello, "a.."));
echo '<br><br>';
var_dump(ltrim($hello, "z..a"));
echo '<br><br>';
var_dump(ltrim($hello, "a..b..c"));
?>