Java String

Java string

Created By: chatGPT

In Java, a String is a special class that represents a sequence of characters. Strings are immutable, meaning once a String object is created, it cannot be changed. Instead, any modification will create a new String object. Here are some common operations you can perform with strings:

To create a string, you can use either single quotes or the String constructor. However, it's more common to use double quotes.

String example1 = "Hello, World!";
String example2 = new String("Hello, Java!");

You can find the length of a string using the length() method. This returns the number of characters in the string, including spaces.

int length = example1.length();  // length = 13

To access a character at a specific index, you can use the charAt(int index) method. Remember that string indexing starts at 0.

char firstChar = example1.charAt(0);  // firstChar = 'H'

Strings can be concatenated using the + operator.

String concatenated = example1 + " " + example2;  // concatenated = "Hello, World! Hello, Java!"

To convert a string to uppercase or lowercase, you can use the toUpperCase() and toLowerCase() methods, respectively.

String upperCase = example1.toUpperCase();  // upperCase = "HELLO, WORLD!"
String lowerCase = example2.toLowerCase();  // lowerCase = "hello, java!"

To check if a string contains a substring, the contains() method is quite handy.

boolean containsWorld = example1.contains("World");  // containsWorld = true

Lastly, to compare two strings, you can use the equals() method, which checks for content equality, or compareTo() method for lexicographical comparison.

boolean isEqual = example1.equals(example2);  // isEqual = false
int comparison = example1.compareTo(example2);  // comparison may be negative, zero, or positive