Question

give me different ways of using string code with examples

Answer 1

public class StringExample {
    public static void main(String[] args) {
        // 1. Creation and Initialization
        String str1 = "Java Programming"; // String literal (stored in String Pool)
        String str2 = new String("Java Programming"); // Using 'new' keyword (stored in Heap)

        // 2. Accessing Information
        int length = str1.length(); // Returns total characters (16)
        char firstChar = str1.charAt(0); // Returns 'J'
        int index = str1.indexOf("Prog"); // Returns 5

        // 3. Transformation (Returns new strings)
        String upper = str1.toUpperCase(); // "JAVA PROGRAMMING"
        String lower = str1.toLowerCase(); // "java programming"
        String sub = str1.substring(0, 4); // Extracts "Java"
        String replaced = str1.replace("Java", "Advanced"); // "Advanced Programming"

        // 4. Comparison
        boolean isEqual = str1.equals(str2); // true (checks content)
        boolean sameRef = (str1 == str2); // false (checks memory reference)
        boolean ignoreCase = str1.equalsIgnoreCase("JAVA programming"); // true

        // 5. Manipulation Tools
        String messy = "  Hello Java  ";
        String clean = messy.trim(); // "Hello Java" (removes outer spaces)
        
        String data = "apple,banana,cherry";
        String[] fruits = data.split(","); // Splits into String array

        // 6. Efficient Concatenation (StringBuilder)
        StringBuilder sb = new StringBuilder("Building"); // Mutable sequence
        sb.append(" a ").append("string..."); // Faster for multiple modifications
        String result = sb.toString();

        // Outputs
        System.out.println("Original: " + str1);
        System.out.println("Substring: " + sub);
        System.out.println("Joined via StringBuilder: " + result);
    }
}

Answer 2

For loop, While loop and Do while loop

Answer 3

if you’re talking Java String usage, there’s a ton of ways beyond the usual literal vs new String(). some of my go-to patterns:

• String concatenation & formatting

String name = "Hilton"; String greeting = "Hello, " + name + "!"; // simple + String formatted = String.format("Hello, %s!", name); // cleaner for complex strings

• StringBuilder / StringBuffer for mutable stuff

StringBuilder sb = new StringBuilder(); sb.append("Java").append(" Strings").append(" rock"); String result = sb.toString();

• Substring, replace, and regex

String str = "apple,banana,cherry"; String[] fruits = str.split(","); // array of fruits String replaced = str.replace("banana", "orange"); String sub = str.substring(0, 5); // "apple"

• Comparisons & checks

str.equalsIgnoreCase("APPLE,BANANA,CHERRY"); // true str.startsWith("apple"); // true str.contains("banana"); // true

• Looping over chars

for(char c : str.toCharArray()){ System.out.println(c); }

basically, if you mix literals, builders, formatting, and regex, you can cover almost any string manipulation in Java without ever hitting performance issues.