There are many string routines in C#. Many of them are called using dot notation and are called methods. A complete list of string manipulation methods can be found at Internet. ;
Let's get acquainted with a couple of the simplest and most useful of them.
string s = "aAbBcC11"
string sUp = s.ToUpper() // sUp = "AABBCC11" - a method that converts each character of a string to uppercase
string sLow = s.ToLower() // sLow = "aabbcc11" - a method that converts each character of a string to lowercase
To the left of the dot is the name of the string (or the string itself in quotes) to which the method is to be applied, and to the right of the dot is the name of the method. The method is always written with parentheses. Any parameters can go inside the brackets if they are needed.
|
To search within a string in C#, the IndexOfAny(Char []) and LastIndexOfAny(Char[]);
IndexOfAny(Char) Returns the zero-based index position of the first occurrence in this instance of any one or more characters specified in a Unicode character array.
LastIndexOfAny(Char[]) does the same, only returns the index of the last occurrence.
When the substring is not found, the methods return -1.
string welcome = "Hello world! Goodbye world!"
int x = welcome.IndexOfAny(new Char[] {'w'}); // 6
Please note: these methods do not look for the number of occurrences, but only determine whether there is such a substring in the string or not.
To remove a substring, you can use the Remove(Int32, Int32) method - it removes the substring from the first specified index to the second.
string welcome = "Hello world! Goodbye world!";
string cut = welcome.Remove(1, 3); // "Ho world! Goodbye world!"
|
To replace one substring with another in a string in C#, use the method Replace(). There are two use cases:
Replace(char old, char new) - char old replaced with char new;
Replace(string old, string new) - string old is replaced by string new, i.e. more than one character can be replaced.
Inline replacement example in C#:
string phone = "+1-234-567-89-10";
// hyphens are changed to spaces
string edited_phone = phone.Replace("-", " ");
// +1 234 567 89 10
|