(PHP 4, PHP 5)

ltrim — Удаляет пробелы из начала строки


string ltrim ( string $str [, string $charlist ] )

Замечание: Второй аргумент был добавлен в PHP 4.1.0

Эта функция возвращает строку str с удаленными из начала строки пробелами. Если второй параметр не передан, ltrim() удаляет следующие символы:

  • " " (ASCII 32 (0x20)), символ пробела.
  • "\t" (ASCII 9 (0x09)), символ табуляции.
  • "\n" (ASCII 10 (0x0A)), символ перевода строки.
  • "\r" (ASCII 13 (0x0D)), символ возврата каретки.
  • "\0" (ASCII 0 (0x00)), NUL-байт.
  • "\x0B" (ASCII 11 (0x0B)), вертикальная табуляция.

Можно также задать список символов для удаления с помощью аргумента charlist . С помощью .. можно задать диапазон символов.

Пример #1 Пример использования ltrim()


"\t\tЛишь несколько слов :) ...  ";
$trimmed ltrim($text);
// $trimmed = "Лишь несколько слов :) ...  "
$trimmed ltrim($text" \t.");
// $trimmed = "Лишь несколько слов :) ...  "
$clean ltrim($binary"\x00..\x1F");
// удалить управляющие символы ASCII из начала строки $binary 
// (от 0 до 31 включительно)


См. также описание функций trim() и rtrim().


To remove leading/trailing zeroes (example: "0123.4560"), doing a += 0 is easier than trim tricks.
2006-08-06 15:13:48
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).
2008-02-04 16:42:31
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
(float) $temp;
  if (
$number $limit) {
$number += 0;
  } else {

Code is untested, but probably sound.
2011-01-08 14:03:33
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:
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.
2011-07-25 04:27:23
+=0 not valid for something like 0000-5. Result is 0
2013-12-10 23:55:22
What i found and i can't get why:

$word = 'stw_weight';
echo ltrim($word, 'stw_');

output:  eight instead weight

If anybody know plz let me know
2014-03-11 23:37:07

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.
2014-04-08 13:33:11
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.
2015-10-29 12:11:34
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)
2017-11-30 15:36:58

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