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


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


La chaîne d'entrée.


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.


Exemple #1 Exemple avec ltrim()


= "\t\tThese are a few words :) ... ";
$binary = "\x09Example string\x0A";
$hello = "Hello World";
var_dump($text, $binary, $hello);


$trimmed = ltrim($text);

$trimmed = ltrim($text, " \t.");

$trimmed = ltrim($hello, "Hdle");

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


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 8 notes

tavi undersc 10 from yahoocom
7 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.
Usamah M dot Ali (usamah1228 at gmail dot com)
15 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).
dzek dot remove_this at dzek dot eu
11 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:
= 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.
5 years ago
I noticed one thing.

Suppose you have to ltrim zeroes from strings like "015", "002", etc. and convert them back to numbers, eg. using intval.

Suppose you must convert to number "000" too.

In this case:

$trimmedString = ltrim('000', '0');

the value of $trimmedString would be NULL (and I think the docs should mention this).

Anyway, I initially thought I had to conditional check for this '000', but I found that intval(NULL) returns 0 (this thing is not in the docs of intval but is in a comment)
mroeling at exed dot nl
9 years ago

The problem is that the character mask (_stw in your case) isn't a literal string, but a character collection. So all characters within _stw are stripped. In your case this includes the w of weight also.
John Sherwood
16 years ago
To remove leading/trailing zeroes (example: "0123.4560"), doing a += 0 is easier than trim tricks.
juan at ecogomera dot com
9 years ago
+=0 not valid for something like 0000-5. Result is 0
12 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. 
function remove_leading_zeros_from_number($number_string) {
$limit = 9000.1
= $number
(float) $temp;
  if (
$number < $limit) {
$number += 0;
  } else {

Code is untested, but probably sound.
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