localeconv
To remove leading/trailing zeroes (example: "0123.4560"), doing a += 0 is easier than trim tricks.
ltrim
(PHP 4, PHP 5)
ltrim — Entfernt Leerraum (oder andere Zeichen) vom Anfang eines Strings
Beschreibung
string ltrim
( string
$str
[, string $charlist
] )Entfernt Leerraum (oder andere Zeichen) vom Anfang eines Strings.
Parameter-Liste
-
str -
Die Eingabezeichenkette.
-
charlist -
Sie können mittels des
charlist-Parameters eigene Zeichen angeben, die Sie entfernen lassen möchten. Führen Sie einfach alle zu löschenden Zeichen auf. Mittels .. können Sie einen Bereich von Zeichen benennen.
Rückgabewerte
Diese Funktion gibt den String str zurück, von
dessen Anfang alle Whitespaces entfernt wurden. Ohne den zweiten Parameter
entfernt ltrim() diese Zeichen:
- " " (ASCII 32 (0x20)), ein einfaches Leerzeichen.
- "\t" (ASCII 9 (0x09)), ein Tabulator.
- "\n" (ASCII 10 (0x0A)), ein Zeilenvorschub (line feed).
- "\r" (ASCII 13 (0x0D)), ein Wagenrücklauf-Zeichen (carriage return).
- "\0" (ASCII 0 (0x00)), das NUL-Byte.
- "\x0B" (ASCII 11 (0x0B)), ein vertikaler Tabulator.
Changelog
| Version | Beschreibung |
|---|---|
| 4.1.0 |
Der Parameter charlist wurde hinzugefügt.
|
Beispiele
Beispiel #1 Beispiel zur Verwendung von ltrim()
<?php
$text = "\t\tThese are a few words :) ... ";
$binary = "\x09Example string\x0A";
$hello = "Hello World";
var_dump($text, $binary, $hello);
print "\n";
$trimmed = ltrim($text);
var_dump($trimmed);
$trimmed = ltrim($text, " \t.");
var_dump($trimmed);
$trimmed = ltrim($hello, "Hdle");
var_dump($trimmed);
// entfernt die ASCII Steuerzeichen vom Beginn von $binary
// (von 0 bis einschließlich 31)
$clean = ltrim($binary, "\x00..\x1F");
var_dump($clean);
?>
Das oben gezeigte Beispiel erzeugt folgende Ausgabe:
string(32) " These are a few words :) ... " string(16) " Example string " string(11) "Hello World" string(30) "These are a few words :) ... " string(30) "These are a few words :) ... " string(7) "o World" string(15) "Example string "
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User Contributed Notes
ltrim - [6 notes]
John Sherwood ¶
6 years ago
dzek dot remove_this at dzek dot eu ¶
1 year ago
Guys, if += 0 is producing wrong values sometimes, and preg_replace is cpu consuming, then just stick to the main function described on that page, and use:
<?php
$value = ltrim($value, '0');
?>
should be the fastest and most reliable.
I think all those comments can be misleading for begginers checking this page - it's sort of using magic tricks to reinvent the wheel.
Mike ¶
2 years ago
Keep in mind the amount of resources preg_replace() uses.
I would suggest a simple if statement if you need to parse through large amounts of data.
<?php
function remove_leading_zeros_from_number($number_string) {
$limit = 9000.1
$temp = $number
(float) $temp;
if ($number < $limit) {
$number += 0;
} else {
preg_replace('~^[0]*([1-9][0-9]*)$~','$1',$number_string)
}
}
?>
Code is untested, but probably sound.
Usamah M dot Ali (usamah1228 at gmail dot com) ¶
5 years ago
For those who use right-to-left languages such as Arabic, Hebrew, etc., it's worth mentioning that ltrim() (which stands for left trim) & rtrim() (which stands for right trim) DO NOT work contextually. The nomenclature is rather semantically incorrect. So in an RTL script, ltrim() will trim text from the right direction (i.e. beginning of RTL strings), and rtrim() will trim text from the left direction (i.e. end of RTL strings).
tanmar.de ¶
3 years ago
The neat trick from Mr. Sherwood has only one ugly side-effect: If the "number" contained in the string is considerably large, you will end up with an int (or float) value that has nothing to do with the original number ...
You may use preg_replace instead:
$number_string = preg_replace('~^[0]*([1-9][0-9]*)$~','$1',$number_string);
This kills any leading zeros safely without changing any other data.
Hope this helps.
pLIMP ¶
10 months ago
Function similar to ltrim only it will remove everything from the start of the string to the last occurence of anything in the $charlist
<?php
function lstrip($string, $charlist) {
// removes everything from start of string to last occurence of char in charlist
$charlist = str_split($charlist);
foreach ($charlist as $char) {
$pos = max(strrpos($string, $char), $pos);
}
$string_stripped = substr($string, $pos + 1);
return $string_stripped;
}
?>