How to use string functions in PHP_PHP Tutorial

How to use string functions in PHP There are many string manipulation functions in PHP. The important ones are as follows:

(1)echo, print, printf, sprintf
The first two functions are to output strings. If in the string If there is a variable name, it will be replaced by its value.
The last two functions are similar to the C functions of the same name.

(2)strchr,strlen,strtok,strrchr,strrev,strstr,strtolower,
strtoupper, substr, ucfirst
These are commonly used string manipulation functions, some of which have the same meaning as the functions of the same name in C.
strrev is to flip a string.
The meaning of strtolower and strtoupper should not need to be explained. .
ucfirst is to capitalize the first character of the string.
substr is to return a substring of the string. The usage is: substr (string, header, length).
Header position It is calculated from 0. If it is a negative number, it means counting forward from the tail.

(3)Chr,Ord
Similar to the function of the same name in C.

( 4)explode, implode, join
These are functions related to arrays.
explode(string, separator) returns an array generated by dividing the string at the separator.
implode(array , delimiter) returns a string formed by inserting a delimiter between each element of the array.
Join has the same meaning as implode.

(5)Chop
Remove the whitespace at the end of the string .

(6)htmlspecialchars
Replace the HTML special characters in the string with their names, for example, "<" becomes "<".

(7)nl2br
Add "
" before each carriage return in the string.

(8)AddSlashes,StripSlashes
Add "" to the string respectively before it can be used Add and remove "" to the characters queried in the database.

(9)parse_str
Analyze strings of type "name1=value1&name2=value2&..." into some variables.
For example:
parse_str("a=1&b=2");
Generate two variables $a and $b, with values ​​​​1 and 2 respectively.
If there are two pairs of names/values ​​with the same name part, then the following The value of one overwrites the previous one.
If the names of these two pairs have "[]" at the end, such as "a[]=1&a[]=2", then the array $a will be generated, and the two elements will be 1. ,2

http://www.bkjia.com/PHPjc/314534.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/314534.htmlTechArticleHow to use string functions in PHP There are many string manipulation functions in PHP, the important ones are as follows These: (1) echo, print, printf, sprintf The first two functions are to output strings. In the string...