Home>Article>Backend Development> 18 commonly used string functions in PHP
String functions are an indispensable part of the basic operations of PHP and one of the most important parts. This article lists and introduces more than a dozen commonly used string operations. I hope it will be helpful to everyone.
String formatting
String truncation:
trim():
Remove characters (carriage return, line feed, tab) at the beginning and end of the string and return the result string
At the same time, the trim() parameter can also set a custom special character filter list
rtrim():
Delete special characters starting from the beginning of the string Characters
ltrim():
Delete special characters starting from the end of the string
chop():
Similar to the rtrim() function
Formatted output:
htmlspecialchars(): Function filtering Output
htmlspecialchars():The function will output a string as an HTML entity (characters with special meanings in the string can be translated into HTML entities)
str_replace(): Regular filter output
nl2br():HTML formatting
nl2br(): The function takes a string as an input operation, use The < br /> tag in HTML replaces the \n symbol in a string; this is useful for displaying a long string on an HTML browser.
Character formatted output: sprintf()/printf()
In character formatted output, use the % character format output control character to normalize characters
String case
strtoupper(): String case
strtolower( ): String lowercase
ucfirst(): Capitalize the first letter
##ucwords(): Change the first character of each English paragraph Upper case
String concatenation and splitting
explode(): Use the specified character as the splitting condition and return to An array
strtok(): Decompose a string into a set of strings
The delimiter can be a character or a string, and the strtok() function each time Only one substring will be read based on the delimiter;substr():
returns a string consisting of the given starting point and end point. New string result string substr(string string, int start [,int length]); The function returns the string content in the string string according to the start and length constraintsString comparison
Sort:
strcmp(): Compare two strings
strcasecmp(): Compare strings (not case sensitive)
strnatcmp(): Natural Sorting (not case sensitive)
strlen(): Determine the length of the string
Character matching
String search:
strstr(): Match the search character or string
strchr(): Match and search for a character
strstr() and strchr() are equally effective in matching and searching applications; the function requires more than two parameters, the first parameter is: needs to be Search string, the second parameter is: the target keyword to be searched; matching the string to the keyword will return the searched string, otherwise return falsecharacters String position:
strpos(): Returns the position of the matched character
strpos():Parameters of the function Similar to strstr(), the third parameter of strpos() can specify the position to start searching
String replacement:
str_replace(): String replaces other characters in the string.
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