php вставка символа в строку

substr

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

substr — Возвращает подстроку

Описание

Список параметров

Если string меньше offset символов, будет возвращена пустая строка.

Пример #1 Использование отрицательного параметра offset

Если length положительный, возвращаемая строка будет не длиннее length символов, начиная с параметра offset (в зависимости от длины string ).

Если параметр length опущен, то будет возвращена подстрока, начинающаяся с позиции, указанной параметром offset и длящейся до конца строки.

Пример #2 Использование отрицательного параметра length

Возвращаемые значения

Возвращает извлечённую часть параметра string или пустую строку.

Список изменений

Примеры

Пример #3 Базовое использование substr()

Пример #4 substr() и приведение типов

class apple <
public function __toString () <
return «green» ;
>
>

Результат выполнения данного примера:

Пример #5 Недопустимый диапазон символов

Результат выполнения данного примера в PHP 8:

Результат выполнения данного примера в PHP 7:

Смотрите также

User Contributed Notes 36 notes

For getting a substring of UTF-8 characters, I highly recommend mb_substr

may be by following functions will be easier to extract the needed sub parts from a string:

Coming to PHP from classic ASP I am used to the Left() and Right() functions built into ASP so I did a quick PHPversion. hope these help someone else making the switch

Shortens the filename and its expansion has seen.

### SUB STRING BY WORD USING substr() and strpos() #####

### THIS SCRIPT WILL RETURN PART OF STRING WITHOUT WORD BREAK ###

Drop extensions of a file (even from a file location string)

= «c:/some dir/abc defg. hi.jklmn» ;

?>

output: c:/some dir/abc defg. hi

Hope it may help somebody like me.. (^_^)

PS:I’m sorry my english is too poor. 🙁

If you want to have a string BETWEEN two strings, just use this function:

$string = «123456789» ;
$a = «12» ;
$b = «9» ;

If you need to parse utf-8 strings char by char, try this one:

Be aware of a slight inconsistency between substr and mb_substr

mb_substr(«», 4); returns empty string

substr(«», 4); returns boolean false

tested in PHP 7.1.11 (Fedora 26) and PHP 5.4.16 (CentOS 7.4)

I wanted to work out the fastest way to get the first few characters from a string, so I ran the following experiment to compare substr, direct string access and strstr:

(substr) 3.24
(direct access) 11.49
(strstr) 4.96

(With standard deviations 0.01, 0.02 and 0.04)

THEREFORE substr is the fastest of the three methods for getting the first few letters of a string.

Here we have gr8 function which simply convert ip address to a number using substr with negative offset.
You can need it if you want to compare some IP addresses converted to a numbers.
For example when using ip2country, or eliminating same range of ip addresses from your website 😀

$min = ip2no ( «10.11.1.0» );
$max = ip2no ( «111.11.1.0» );
$visitor = ip2no ( «105.1.20.200» );

I created some functions for entity-safe splitting+lengthcounting:

I needed a function like lpad from oracle, or right from SQL
then I use this code :

Just a little function to cut a string by the wanted amount. Works in both directions.

Anyone coming from the Python world will be accustomed to making substrings by using a «slice index» on a string. The following function emulates basic Python string slice behavior. (A more elaborate version could be made to support array input as well as string, and the optional third «step» argument.)

The output from the examples:
c
cd
cdefg
abcd
abcd
efg

I have developed a function with a similar outcome to jay’s

Checks if the last character is or isnt a space. (does it the normal way if it is)
It explodes the string into an array of seperate works, the effect is. it chops off anything after and including the last space.

I needed to cut a string after x chars at a html converted utf-8 text (for example Japanese text like 嬰謰弰脰欰罏).
The problem was, the different length of the signs, so I wrote the following function to handle that.
Perhaps it helps.

Using a 0 as the last parameter for substr().

[English]
I created python similar accesing list or string with php substr & strrev functions.

About of pattern structures
[start:stop:step]

?>

Using this is similar to simple substr.

Источник

Функции для работы со строками

Для получения информации о более сложной обработке строк обратитесь к функциями Perl-совместимых регулярных выражений. Для работы с многобайтовыми кодировками посмотрите на функции по работе с многобайтовыми кодировками.

Содержание

User Contributed Notes 24 notes

In response to hackajar yahoo com,

No string-to-array function exists because it is not needed. If you reference a string with an offset like you do with an array, the character at that offset will be return. This is documented in section III.11’s «Strings» article under the «String access and modification by character» heading.

I’m converting 30 year old code and needed a string TAB function:

//tab function similar to TAB used in old BASIC languages
//though some of them did not truncate if the string were
//longer than the requested position
function tab($instring=»»,$topos=0) <
if(strlen($instring)

I use these little doo-dads quite a bit. I just thought I’d share them and maybe save someone a little time. No biggy. 🙂

Just a note in regards to bloopletech a few posts down:

The word «and» should not be used when converting numbers to text. «And» (at least in US English) should only be used to indicate the decimal place.

Example:
1,796,706 => one million, seven hundred ninety-six thousand, seven hundred six.
594,359.34 => five hundred ninety four thousand, three hundred fifty nine and thirty four hundredths

/*
* example
* accept only alphanum caracteres from the GET/POST parameters ‘a’
*/

to: james dot d dot baker at gmail dot com

PHP has a builtin function for doing what your function does,

/**
Utility class: static methods for cleaning & escaping untrusted (i.e.
user-supplied) strings.

Any string can (usually) be thought of as being in one of these ‘modes’:

pure = what the user actually typed / what you want to see on the page /
what is actually stored in the DB
gpc = incoming GET, POST or COOKIE data
sql = escaped for passing safely to RDBMS via SQL (also, data from DB
queries and file reads if you have magic_quotes_runtime on—which
is rare)
html = safe for html display (htmlentities applied)

Always knowing what mode your string is in—using these methods to
convert between modes—will prevent SQL injection and cross-site scripting.

This class refers to its own namespace (so it can work in PHP 4—there is no
self keyword until PHP 5). Do not change the name of the class w/o changing
all the internal references.

Example usage: a POST value that you want to query with:
$username = Str::gpc2sql($_POST[‘username’]);
*/

Example: Give me everything up to the fourth occurance of ‘/’.

//
// string strtrmvistl( string str, [int maxlen = 64],
// [bool right_justify = false],
// [string delimter = «
\n»])
//
// splits a long string into two chunks (a start and an end chunk)
// of a given maximum length and seperates them by a given delimeter.
// a second chunk can be right-justified within maxlen.
// may be used to ‘spread’ a string over two lines.
//

I really searched for a function that would do this as I’ve seen it in other languages but I couldn’t find it here. This is particularily useful when combined with substr() to take the first part of a string up to a certain point.

?>

Example: Give me everything up to the fourth occurance of ‘/’.

The functions below:

Are correct, but flawed. You’d need to use the === operator instead:

Here’s an easier way to find nth.

I was looking for a function to find the common substring in 2 different strings. I tried both the mb_string_intersect and string_intersect functions listed here but didn’t work for me. I found the algorithm at http://en.wikibooks.org/wiki/Algorithm_implementation/Strings/Longest_common_substring#PHP so here I post you the function

Here’s a simpler «simplest» way to toggle through a set of 1..n colors for web backgrounds:

If you want a function to return all text in a string up to the Nth occurrence of a substring, try the below function.

(Pommef provided another sample function for this purpose below, but I believe it is incorrect.)

/*
// prints:
S: d24jkdslgjldk2424jgklsjg24jskgldjk24
1: d
2: d24jkdslgjldk
3: d24jkdslgjldk24
4: d24jkdslgjldk2424jgklsjg
5: d24jkdslgjldk2424jgklsjg24jskgldjk
6: d24jkdslgjldk2424jgklsjg24jskgldjk24
7: d24jkdslgjldk2424jgklsjg24jskgldjk24
*/

?>

Note that this function can be combined with wordwrap() to accomplish a routine but fairly difficult web design goal, namely, limiting inline HTML text to a certain number of lines. wordwrap() can break your string using
, and then you can use this function to only return text up to the N’th
.

You will still have to make a conservative guess of the max number of characters per line with wordwrap(), but you can be more precise than if you were simply truncating a multiple-line string with substr().

= ‘Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Pellentesque id massa. Duis sollicitudin ipsum vel diam. Aliquam pulvinar sagittis felis. Nullam hendrerit semper elit. Donec convallis mollis risus. Cras blandit mollis turpis. Vivamus facilisis, sapien at tincidunt accumsan, arcu dolor suscipit sem, tristique convallis ante ante id diam. Curabitur mollis, lacus vel gravida accumsan, enim quam condimentum est, vitae rutrum neque magna ac enim.’ ;

Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Pellentesque id massa. Duis sollicitudin
ipsum vel diam. Aliquam pulvinar sagittis felis. Nullam hendrerit semper elit. Donec convallis
mollis risus. Cras blandit mollis turpis. Vivamus facilisis, sapien at tincidunt accumsan, arcu

Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Pellentesque id massa. Duis sollicitudin
ipsum vel diam. Aliquam pulvinar sagittis felis. Nullam hendrerit semper elit. Donec convallis
mollis risus. Cras blandit mollis turpis. Vivamus facilisis, sapien at tincidunt accumsan, arcu
dolor suscipit sem, tristique convallis ante ante id diam. Curabitur mollis, lacus vel gravida

Источник

substr_replace

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

substr_replace — Заменяет часть строки

Описание

Список параметров

Возвращаемые значения

Возвращает результирующую строку. Если string является массивом, то возвращает массив.

Список изменений

Примеры

Пример #1 Простой пример использования substr_replace()

Пример #2 Использование substr_replace() для одновременной множественной замены строк

Результат выполнения данного примера:

Примечания

Замечание: Эта функция безопасна для обработки данных в двоичной форме.

Смотрите также

User Contributed Notes 35 notes

Forget all of the mb_substr_replace() implementations mentioned in this page, they’re all buggy.

Here is a version that mimics the behavior of substr_replace() exactly:

PHP version of Java’s removeCharAt() function:

Using substr_replace() can be avoided by using substr() instead:

This can be useful when you need to replace parts of multibyte strings like strings encoded with utf-8. There isn’t a multibute variant for substr_replace(), but for php substr() there is mb_substr(). For more information on multibyte strings see http://nl3.php.net/manual/en/ref.mbstring.php

I’ve just taken a look at the post by ntoniazzi and I have a very small correction to make.

In the second if statement, it should be a triple equals, so:

I wrote a function that you can use for example in combination with a search script to cut off the articles that are too long.

I recently ran across a situation where I need to strip a heavily nested html list such that only the top level was preserved. I started with a regular expression solution, but found that I kept matching the wrong closing ul with an outer opening ul.

This was my alternative solution, and it seems to work well:

?>

Hope this helps someone.

This will truncate a longer string to a smaller string of specified length while replacing the middle portion with a separator exactly in the middle.

//prints «abcdefghij/. /56789z.jpg»

I have a little function that works like substr_replace () what I use for some purpose. Maybe someone needs it.

This is a small powerful function that performs its job flawlessly.

I suggest changing the function suggested by Guru Evi slightly. I found that it doesn’t work as written here.

If your string is not long enough to meet what you specify in start and length then the replacement string is added towards the end of the string.

I use strip_tags to strip out the HTML otherwise you might get a screwed up HTML (when a tags open in the string, but because you cut-off it doesn’t)

THE DOT DOT DOT ISSUE

PROBLEM:
You want to abbreviate a string.
E.g. You want «BritneySpears» to show as «BritneySpe. «, being only the ten first characters followed by «. «

This will result in BritneySpe.

The older function would end up looking like «blah blah. » or «blah blah. » which doesn’t look so nice to me.

$punctuation = «. ;,-» ; //punctuation you want removed

Here is a simple function to shorten a string and add an ellipsis

This may be obvious to others, but I just spent hours and my feeble brain only caught up to it after a long break.

If you are looping through a string which has multiple substrings that need to be replaced, you have to add an offset factor to each original offset before you replaced any strings. Here is a real world example:

From draft.js we get paragraphs with multiple links designated only with offset, anchor text length, url, target. So each anchor text must be wrapped in the anchortext to save proper content in the database.

Here is the implementation of offset factor:

I hope this helps a noobie 🙂 If there is another easier way, I would love to hear about it.

First Example can be simplified =>

$input = array(‘A: XXX’, ‘B: XXX’, ‘C: XXX’);

output: Array ( [0] => A: YYY [1] => B: YYY [2] => C: YYY )

I recently needed a routine that would remove the characters in one string from another, like the regex

I don’t know if this function is multibyte safe but I’ve written a function that will do the same in multibyte mode.

Just to add to the examples, if replacement is longer than length, only the length number of chars are removed from string and all of replacement is put in its place, and therefor strlen($string) is inreased.

$var = ‘ABCDEFGH:/MNRPQR/’;
/* Should return ABCDEFGH:/testingRPQR/ */
echo substr_replace ($var, ‘testing’, 10, 2);

If you would like to remove characters from the start or end of a string, try the substr() function.

The comment by geniusdex is a good one. Short, simple functions are the best. But if the string is not longer than the limit set, NOTHING is returned. Here is the function re-done to always return a string:

Regarding «. «, even the short functions are too long and complicated, and there’s no need to use substr_replace. substr() works better and is way faster prior to 4.3.5 as the below poster stated.

This is my version of making dotted strings:

To abbreviate links into ‘. ‘ if they outreach a certain amount of space; use the preg_replace function instead.

For instance you grabbed the headlines of a news site for use on your own page and the lines are to long:

Источник