iconv_substr(3) [php man page]
ICONV_SUBSTR(3) 1 ICONV_SUBSTR(3)
iconv_substr - Cut out part of a string
SYNOPSIS
string iconv_substr (string $str, int $offset, [int $length = iconv_strlen($str, $charset)], [string $charset = ini_get("iconv.inter-
nal_encoding")])
DESCRIPTION
Cuts a portion of $str specified by the $offset and $length parameters.
PARAMETERS
o $str
- The original string.
o $offset
- If $offset is non-negative, iconv_substr(3) cuts the portion out of $str beginning at $offset'th character, counting from zero.
If $offset is negative, iconv_substr(3) cuts out the portion beginning at the position, $offset characters away from the end of
$str.
o $length
- If $length is given and is positive, the return value will contain at most $length characters of the portion that begins at
$offset (depending on the length of $string). If negative $length is passed, iconv_substr(3) cuts the portion out of $str from
the $offset'th character up to the character that is $length characters away from the end of the string. In case $offset is also
negative, the start position is calculated beforehand according to the rule explained above.
o $charset
- If $charset parameter is omitted, $string are assumed to be encoded in iconv.internal_encoding. Note that $offset and $length
parameters are always deemed to represent offsets that are calculated on the basis of the character set determined by $charset,
whilst the counterpart substr(3) always takes these for byte offsets.
RETURN VALUES
Returns the portion of $str specified by the $offset and $length parameters.
If $str is shorter than $offset characters long, FALSE will be returned.
SEE ALSO
substr(3), mb_substr(3), mb_strcut(3).
PHP Documentation Group ICONV_SUBSTR(3)
Check Out this Related Man Page
SUBSTR(3) 1 SUBSTR(3)
substr - Return part of a string
SYNOPSIS
string substr (string $string, int $start, [int $length])
DESCRIPTION
Returns the portion of $string specified by the $start and $length parameters.
PARAMETERS
o $string
- The input string. Must be one character or longer.
o $start
- If $start is non-negative, the returned string will start at the $start'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
$start is negative, the returned string will start at the $start'th character from the end of $string. If $string is less than or
equal to $start characters long, FALSE will be returned.
Example #1
Using a negative $start
<?php
$rest = substr("abcdef", -1); // returns "f"
$rest = substr("abcdef", -2); // returns "ef"
$rest = substr("abcdef", -3, 1); // returns "d"
?>
o $length
- If $length is given and is positive, the string returned will contain at most $length characters beginning from $start (depend-
ing 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 $start is negative). If $start denotes the position of this trunca-
tion or beyond, false will be returned. If $length is given and is 0, FALSE or NULL, an empty string will be returned. If
$length is omitted, the substring starting from $start until the end of the string will be returned.
Example #2
Using a negative $length
<?php
$rest = substr("abcdef", 0, -1); // returns "abcde"
$rest = substr("abcdef", 2, -1); // returns "cde"
$rest = substr("abcdef", 4, -4); // returns false
$rest = substr("abcdef", -3, -1); // returns "de"
?>
RETURN VALUES
Returns the extracted part of $string; or FALSE on failure, or an empty string.
CHANGELOG
+--------------+---------------------------------------------------+
| Version | |
| | |
| | Description |
| | |
+--------------+---------------------------------------------------+
|5.2.2 - 5.2.6 | |
| | |
| | If the $start parameter indicates the position |
| | of a negative truncation or beyond, false is |
| | returned. Other versions get the string from |
| | start. |
| | |
+--------------+---------------------------------------------------+
EXAMPLES
Example #3
Basic substr(3) usage
<?php
echo substr('abcdef', 1); // bcdef
echo substr('abcdef', 1, 3); // bcd
echo substr('abcdef', 0, 4); // abcd
echo substr('abcdef', 0, 8); // abcdef
echo substr('abcdef', -1, 1); // f
// Accessing single characters in a string
// can also be achieved using "square brackets"
$string = 'abcdef';
echo $string[0]; // a
echo $string[3]; // d
echo $string[strlen($string)-1]; // f
?>
Example #4
substr(3) casting behaviour
<?php
class apple {
public function __toString() {
return "green";
}
}
echo "1) ".var_export(substr("pear", 0, 2), true).PHP_EOL;
echo "2) ".var_export(substr(54321, 0, 2), true).PHP_EOL;
echo "3) ".var_export(substr(new apple(), 0, 2), true).PHP_EOL;
echo "4) ".var_export(substr(true, 0, 1), true).PHP_EOL;
echo "5) ".var_export(substr(false, 0, 1), true).PHP_EOL;
echo "6) ".var_export(substr("", 0, 1), true).PHP_EOL;
echo "7) ".var_export(substr(1.2e3, 0, 4), true).PHP_EOL;
?>
The above example will output:
1) 'pe'
2) '54'
3) 'gr'
4) '1'
5) false
6) false
7) '1200'
ERRORS
/EXCEPTIONS
Returns FALSE on error.
Example #5
<?php
var_dump(substr('a', 1)); // bool(false)
?>
SEE ALSO
strrchr(3), substr_replace(3), preg_match(3), trim(3), mb_substr(3), wordwrap(3), String access and modification by character.
PHP Documentation Group SUBSTR(3)