In PHP you can access characters of strings in a few different ways, one of which is substr[]. You can also access the Nth character in a string with curly or square braces, like so:
$string = 'hello';
echo $string{0}; // h
echo $string[0]; // h
My question is, is there a benefit of one over the other? What's the difference between {} and []?
Thanks.
asked Dec 2, 2008 at 19:50
0
use $string[0], the other method [braces] has been
removed in PHP 8.0.
For strings:
Accessing characters within string literals using the {} syntax has been deprecated in PHP 7.4. This has been removed in PHP 8.0.
And for arrays:
Prior to PHP 8.0.0, square brackets and curly braces could be used interchangeably for accessing array elements [e.g. $array[42] and $array{42} would both do the same thing in the example above]. The curly brace syntax was deprecated as of PHP 7.4.0 and no longer supported as of PHP 8.0.0.
IMSoP
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answered Dec 2, 2008 at 19:54
OwenOwen
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There is no difference. Owen's answer is outdated, the latest version of PHP Manual no longer states that it is deprecated §:
Characters within strings may be accessed and modified by specifying the zero-based offset of the desired character after the string using square array brackets, as in
$str[42]. Think of a string as an array of characters for this purpose. [...]Note: Strings may also be accessed using braces, as in
$str{42}, for the same purpose.
However it seems that more people/projects use [], and that many people don't even know {} is possible. If you need to share your code publicly or with people who don't know the curly brace syntax, it may be beneficial to use [].
UPDATED : accessing string characters with {} is deprecated, use [] instead.
answered Nov 7, 2014 at 18:47
PacerierPacerier
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answered Jun 13, 2016 at 3:10
Pedro GimenoPedro Gimeno
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Curly brace access was deprecated in PHP 7.4
Array and string offset access using curly braces ¶
The array and string offset access syntax using curly braces is deprecated. Use $var[$idx] instead of $var{$idx}.
PHP 7.4 Deprecated Features, PHP Core
answered Mar 1 at 15:59
[PHP 4, PHP 5, PHP 7, PHP 8]
substr — Return part of a string
Description
substr[string $string, int $offset, ?int $length = null]: string
Parameters
stringThe input string.
offset If offset is non-negative, the returned string will start at the offset'th position in string, counting from zero. For instance, in the string 'abcdef', the character at position 0 is 'a', the character at position 2 is 'c', and so forth.
If offset is negative, the returned string will start at the
offset'th character from the end of string.
If string is less than offset characters long, an empty string will be returned.
Example #1 Using a negative offset
length If length is given and is positive, the string returned will contain at most length characters beginning from offset [depending on the length of string].
If length is given and is
negative, then that many characters will be omitted from the end of string [after the start position has been calculated when a offset is negative]. If offset denotes the position of this truncation or beyond, an empty string will be returned.
If length is given and is 0, an empty string will be returned.
If length is omitted or null, the substring starting from offset until the end of the string will be returned.
Example #2 Using a negative length
Return Values
Returns the extracted part of string, or an empty string.
Changelog
| 8.0.0 | length is nullable now. When length is explicitly set to null, the function returns a substring finishing at the end of the string, when it previously returned an empty string.
|
| 8.0.0 | The function returns an empty string where it previously returned false.
|
Examples
Example #3 Basic substr[] usage
Example #4 substr[] casting behaviour
The above example will output:
1] 'pe' 2] '54' 3] 'gr' 4] '1' 5] '' 6] '' 7] '1200'
Example #5 Invalid Character Range
If an invalid character range is requested, substr[] returns an empty string as of PHP 8.0.0; previously, false was returned instead.
Output of the above example in PHP 8:
Output of the above example in PHP 7:
See Also
- strrchr[] - Find the last occurrence of a character in a string
- substr_replace[] - Replace text within a portion of a string
- preg_match[] - Perform a regular expression match
- trim[] - Strip whitespace [or other characters] from the beginning and end of a string
- mb_substr[] - Get part of string
- wordwrap[] - Wraps a string to a given number of characters
- String access and modification by character
Andreas Bur [andreas dot buro at gmail dot com] ¶
13 years ago
For getting a substring of UTF-8 characters, I highly recommend mb_substr
biohazard dot ge at gmail dot com ¶
9 years ago
may be by following functions will be easier to extract the needed sub parts from a string:
here comes the source:
bleakwind at msn dot com ¶
17 years ago
This returns the portion of str specified by the start and length parameters..
It can performs multi-byte safe on number of characters. like mb_strcut[] ...
Note:
1.Use it like this bite_str[string str, int start, int length [,byte of on string]];
2.First character's position is 0. Second character position is 1, and so on...
3.$byte is one character length of your encoding, For example: utf-8 is "3", gb2312 and big5 is "2"...you can use the function strlen[] get it...
Enjoy it :] ...
--- Bleakwind
QQ:940641
//www.weaverdream.com
PS:I'm sorry my english is too poor... :[
pugazhenthi k ¶
9 years ago
nikolai dot wuestemann at t-online dot de ¶
11 years ago
If you want to have a string BETWEEN two strings, just use this function:
greg at apparel dot com ¶
8 years ago
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
function left[$str, $length] {
return substr[$str, 0, $length];
}
function right[$str, $length] {
return substr[$str, -$length];
}
Petez ¶
15 years ago
I wanted to work out the fastest way to get the first few characters from a string, so I ran the following experiment to compare substr, direct string access and strstr:
[substr] 3.24 [With standard deviations 0.01, 0.02 and 0.04] THEREFORE substr is the fastest of the three methods for getting the first few letters of a string.
The string was 6 paragraphs of Lorem Ipsum, and I was trying match the first two words. The experiment was run 3 times and averaged. The results were:
[direct access] 11.49
[strstr] 4.96
gkhelloworld at gmail dot com ¶
13 years ago
Shortens the filename and its expansion has seen.
kaysar in ymail in com ¶
13 years ago
Drop extensions of a file [even from a file location string]
Hope it may help somebody like me.. [^_^]
output: c:/some dir/abc defg. hi
Anonymous ¶
4 years ago
Be aware of a slight inconsistency between substr and mb_substr
mb_substr["", 4]; returns empty string
substr["", 4]; returns boolean false
tested in PHP 7.1.11 [Fedora 26] and PHP 5.4.16 [CentOS 7.4]
fatihmertdogancan at hotmail dot com ¶
8 years ago
[English]
I created python similar accesing list or string with php substr & strrev functions.
Use: str[$string,$pattern]
About the python pattern,
//docs.python.org/release/1.5.1p1/tut/strings.html
//effbot.org/zone/python-list.htm
About of pattern structures
[start:stop:step]
Example,
Output,
thetoacn
eht
aom
htan
This is function phpfiddle link: //phpfiddle.org/main/code/e82-y5d
or source;
Good works..
fanfatal at fanfatal dot pl ¶
17 years ago
Hmm ... this is a script I wrote, whitch is very similar to substr, but it isn't takes html and bbcode for counting and it takes portion of string and show avoided [html & bbcode] tags too ;]
Specially usefull for show part of serach result included html and bbcode tags
Using this is similar to simple substr.
Greatings ;]
...
link ¶
13 years ago
I created some functions for entity-safe splitting+lengthcounting:
pheagey at gmail dot com ¶
10 years ago
Using a 0 as the last parameter for substr[].
As per examples
works no problem. However
will get you nothing. Just a quick heads up
egingell at sisna dot com ¶
15 years ago