We are learningPHP string operations (1) echo, print, printf, sprintf
The first two functions are to output strings. If there is a variable name in the string, it will be replaced with its value.
The latter two functions are similar to the C functions of the same name.
PHP string operations (2) strchr, strlen, strtok, strrchr, strrev, strstr, strtolower,
strtoupper, substr, ucfirst
These are commonly used PHP string operations, some of which have the same meaning as the functions of the same name in C.
strrev is Flip a string. The meaning of
strtolower and strtoupper should be self-explanatory.
ucfirst turns the first character of the string into uppercase.
substr returns a substring of the string. Usage It is: substr (string, header, length).
The head position is calculated from 0. If it is a negative number, it means counting forward from the tail.
PHP string Operation (3) Chr, Ord
is similar to the function of the same name in C.
PHP string operation (4) explode, implode, join
These are functions related to arrays.
explode(string, separator) returns an array produced by dividing the string at the separator.
implode(array, separator) returns an array that will A string formed by inserting delimiters between each element of the array.
join has the same meaning as implode.
PHP string operations (5) Chop
Remove the whitespace at the end of the string.
PHP string operation (6) htmlspecialchars
Replace the HTML special characters in the string with their names, such as "< ;" becomes "<".
PHP String Operation (7)nl2br
Add "< before each carriage return in the string BR>".
PHP string operations (8) AddSlashes, StripSlashes
Add the characters that need to be added to the string with "" to be used in database queries. Up and remove "".
PHP string operation (9) parse_str
Parse the "name1=value1&name2=value2&..." type string into some Variables.
For example:
parse_str("a=1&b=2");
Generate two variables $a and $b, with values 1 and 2 respectively.
If there are two pairs of names/ If the name part of the value is the same, the latter value overwrites the previous one.
If the names of these two pairs have "[]" at the end, such as "a[]=1&a[]=2", an array$ will be generated. a, the two elements are 1, 2