Strings and common operations

1 Learn

A String is text. In Java, String is a class, so strings are objects with useful methods.

length() gives the number of characters, toUpperCase() makes capitals, charAt(i) gets one character.

Compare strings with equals(), not ==. == checks if they are the same object, not the same text.

Want more detail? Open the full lesson

2 See the Code

Java

public class Words {
    public static void main(String[] args) {
        String city = "Hyderabad";
        System.out.println(city.length());
        System.out.println(city.toUpperCase());
        System.out.println(city.charAt(0));
        System.out.println(city.equals("Hyderabad"));
    }
}

Hyderabad has 9 characters.
toUpperCase() returns a new String in capitals; city itself is unchanged.
charAt(0) is the first character, H.

Output

9
HYDERABAD
H
true

3 Practice

Ask yourself: print the last character of any word using charAt(word.length() - 1).

Try it in your own Java setup or write it in the Practice Notebook.

4 Quick Check

1. How should you compare two Strings' text?
2. "Java".length() is?

Step 5

Answer and check the Quick Check above to unlock this.

Day 10