Strings

String is a sequence of symbols. All of the symbols can be accessed via their indexes starting from 0.

Indexes

Let's say we have the string "computer". It's structure is the following:

So if we need to print the first letter (c) and the 3rd letter (m), we do:

string word = "computer"; char symbol1 = word[0]; char symbol2 = word[2]; Console.Write(symbol1); Console.Write(symbol2);

Output:

cm

Length

Length is the count of the symbols contained in a string.

It's accessed via the Length property.

Example:

string word = "Hello!"; Console.WriteLine(word.Length);

Output:

6

Via Length we can access the last symbol of a string.

Example:

string str = "The quick brown fox jumps over the lazy dog!"; Console.Write(str[str.Length - 1]);

Output:

!

Access outside of bounds

Accessing string outside of it's bounds results in exception.

Let's look the following example:

string str = "Phone"; char symbol = str[5];

The string has indexes from 0 to 4. Accessing index outside of that bound (in this case 5) causes exception.

Contains

We can check if string is contained in a string via the Contains function.

Examples:

string str = "simple"; Console.WriteLine(str.Contains("m")); Console.WriteLine(str.Contains("si")); Console.WriteLine(str.Contains("z")); Console.WriteLine(str.Contains("S"));

Output:

True True False False

String iteration

All symbols of a string can be iterated via for loop.

Let's print all letters of a word that are not vowels:

using System; namespace Project { class Program { static void Main(string[] args) { string word = "composure"; string vowels = "aeiou"; for (int i = 0; i < word.Length; i++) { string letterToString = word[i] + ""; // Converts char to string. // if letterToString is not contained in the string vowels. if (!vowels.Contains(letterToString)) { Console.Write(letterToString); } } } } }

Output:

cmpsr

In this case !vowels.Contains(letterToString) means that letterToString is a symbol that's not a vowel letter.