Summary of commonly used string functions in php_PHP tutorial
1. Formatted output
chop is an alias of rtrim();
ltrim()
trim()
nl2br() converts n into
print,echo,printf(),sprintf():
echo() is not a function, print() is a function with return values, boolen, false, true;
printf() formatted output
--function, formats the text and then outputs it. It directly calls the system call for IO. It is non-buffered. For example:
$name="hunte";
$age=25;
printf("my name is %s, age %d", $name, $age);
sprintf() formats the string and assigns it to a variable, but does not output it, similar to c
echo nl2br("foo isn'tn bar");
echo "foo isn'tn bar";
?>
--Similar to printf, but does not print, but returns formatted text. The rest is the same as printf. For example:
char sql[256];
sprintf(sql,"select * from table where no = '%s'",bankno);
Its function is just to assign the statements in "" to The variable sql.
strtolower
strtoupper
ucwords
ucfirst
2. String concatenation and segmentation
(1 ) array explode(string input, string separator, int limit)
Use one string to split another string
// Example 1
$pizza = "piece1 piece2 piece3 piece4 piece5 piece6";
$pieces = explode(" ", $pizza);
echo $pieces[0]; // piece1
echo $pieces[1]; // piece2
// Example 2
$data = "foo:*:1023:1000::/home/foo:/bin/sh";
list($user, $pass, $ uid, $gid, $gecos, $home, $shell) = explode(":", $data);
echo $user; // foo
echo $pass; // *
?>
Example 2. limit parameter example
$str = 'one|two|three|four';
// Positive limit
print_r(explode('|', $str, 2));
// Negative limit
print_r(explode('|', $str, -1));
?>
string strtok( string input ,string separator)
$string = "This istan examplestring";
/* Use tab and newline as tokenizing characters as well */
$tok = strtok($string, "nt");
//Holding spaces, n, t as token split string
while ($tok !== false) {
);
}
?>
Result:
Word=This
Word=is
Word=an
Word=example
Word=string
(2.) Interception of string
$test="Your customer service is excellent";
echo substr($test,1);//// ////our customer service is excellent
echo "
";
echo substr($test,-9);//////The length from the end is 9excellent
echo "
";
echo substr($test,0,4);////The length starting from position 0 is 4Your
echo "
";
echo substr($test ,5,-13);/From the fourth to the last 13 characters customer service
echo "
";
$test="Your customer service is excellent";
echo substr($test,1);
echo "
";
echo substr($test,-11);
echo "
";
echo substr($test,0,6);
echo "
";
echo substr($test,5,-13);
echo "
";
our customer service is excellent
s excellent
Your c
customer service
(3) join() string link
3. string Search
(1) string strstr (string haystack, string needle) Alias: strchr, stristr and strstr are similar and different in that they are not case sensitive
strrchr() On the contrary, search Is the last occurrence of the string
The first occurrence of the string
$email = 'user@example.com';
$domain = strstr( $email, '@');
echo $domain; // prints @example.com
?>
$email = 'user@example.com';
$domain =strstr( $email,'e');
$domain2 =strrchr($email,'e');//The string starting from the last occurrence
echo $domain;
echo "
" ;
echo $domain2;
er@example.com
e.com
(2) Find location
int strpos(string str,string needle , [int offset]) If not found, the return value is false
Returns the position where needle is found in str starting from offset
$eg:$t-'hello world';
echo strpos($t,'o',5);
//7 Starting from the oth position, find the position of the variable o, the result is 7
int strrpos()
5. Replace
str_replace("%body%","blank","
6. Small problem with capitalization
Strpos
Find the position of the first occurrence of a string in a string
Strrpos
Find a character in a string, following the first occurrence The first position after that.
strpos(stripos no case)
strrpos(strripos no case)
strstr
stristr( No case)
str_replace
str_ireplace (No case)

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