LTrim (): Remove spaces or other predefined strings from the left of a string
RTrim (): Deletes a blank string or other predefined character starting at the end of the string
Trim (): Removes white space characters and other predefined characters from both ends of a string
Str_pad (): Fills the string with a new length
Strtolower (): Converts a string to lowercase
Strtoupper (): Converts a string to uppercase
Ucfirst (): Capitalize the first character in a string
NL2BR (): Inserts an HTML line break before each new line of the string
Htmlentities (): Converting characters to HTML entities
Htmlspecialchars (): Convert some pre-defined characters to HTML entities
Stripslashes (): Remove backslash added by the addcslashes () function
Number_format (): Ability to format numbers by thousands of groups
Strip_tags (): Peel off html,xml and PHP tags
Strrev (): Invert string
MD5 (): MD5 calculation of a string
ucwords (): Capitalize the given word and first letter
String formatting functions commonly used in PHP
