ltrim

(PHP 4, PHP 5, PHP 7, PHP 8)

ltrim — Supprime les espaces (ou d'autres caractères) de début de chaîne

Description

ltrim(string $string, string $characters = " \n\r\t\v\x00"): string

Supprime les espaces (ou d'autres caractères) de début de chaîne.

Liste de paramètres

string: La chaîne d'entrée.
characters: Il est aussi possible de spécifier les caractères à supprimer en utilisant le paramètre characters. Listez simplement les caractères que vous voulez supprimer dans ce paramètre. Avec .., vous pourrez spécifier des intervalles de caractères.

Valeurs de retour

Cette fonction retourne la chaîne string, après avoir supprimé les caractères invisibles de début de chaîne. Si le second paramètre characters a été omis, ltrim() supprimera les caractères suivants :

" " (ASCII 32 (0x20)), un espace ordinaire.
"\t" (ASCII 9 (0x09)), une tabulation.
"\n" (ASCII 10 (0x0A)), une nouvelle ligne (line feed).
"\r" (ASCII 13 (0x0D)), un retour chariot (carriage return).
"\0" (ASCII 0 (0x00)), le caractère NUL.
"\v" (ASCII 11 (0x0B)), une tabulation verticale.

Exemples

Exemple #1 Exemple avec 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);

// Supprime les caractères de contrôle ASCII du début de $binary
// (de 0 à 31, inclusif)
$clean = ltrim($binary, "\x00..\x1F");
var_dump($clean);

?>

L'exemple ci-dessus va afficher :

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
"

Voir aussi

trim() - Supprime les espaces (ou d'autres caractères) en début et fin de chaîne
rtrim() - Supprime les espaces (ou d'autres caractères) de fin de chaîne

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User Contributed Notes 3 notes

down

tavi undersc 10 from yahoocom ¶

8 years ago

When using a $character_mask the trimming stops at the first character that is not on that mask.

So in the $string = "Hello world" example with $character_mask = "Hdle", ltrim($hello, $character_mask) goes like this:
1. Check H from "Hello world" => it is in the $character_mask, so remove it
2. Check e from "ello world" => it is in the $character_mask, so remove it
3. Check l from "llo world" => it is in the $character_mask, so remove it
4. Check l from "lo world" => it is in the $character_mask, so remove it
5. Check o from "o world" => it is NOT in the $character_mask, exit the function

Remaining string is "o world".

I hope it helps someone as I had a confusing moment with this function.

down

Usamah M dot Ali (usamah1228 at gmail dot com) ¶

16 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).

down

dzek dot remove_this at dzek dot eu ¶

13 years 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.

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