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ltrim

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

ltrimElimina los espacios (u otros caracteres) del inicio de un string

Descripción

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

Elimina los espacios (u otros caracteres) del inicio de un string.

Parámetros

string
El string de entrada.
characters
Opcionalmente, los caracteres eliminados también se pueden especificar utilizando el parámetro characters. Simplemente enumere todos los caracteres que necesitan ser eliminados. Con .. es posible especificar un rango creciente de caracteres.

Valores devueltos

Esta función devuelve un string con los espacios eliminados al inicio del string.

Ejemplos

Ejemplo #1 Ejemplo con 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);

// Elimina los caracteres de control ASCII del inicio de $binary
// (de 0 a 31, inclusive)
$clean = ltrim($binary, "\x00..\x1F");
var_dump($clean);

?>

El resultado del ejemplo sería:

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
"

Ver también

  • trim() - Elimina los espacios (u otros caracteres) al inicio y al final de un string
  • rtrim() - Elimina los espacios (u otros caracteres) al final de un string
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User Contributed Notes 3 notes

up
88
tavi undersc 10 from yahoocom
9 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.
up
25
Usamah M dot Ali (usamah1228 at gmail dot com)
17 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).
up
4
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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