Example 1

public static void method(int n) {
    int sum = 0;
    for (int i = 1; i <= n; i++) {
        sum++;
        System.out.println(sum);
    }
}    

Example 2 
    
public static void method(int n) {
    int sum = 0;
    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= n; j++) {
            sum++;
        }
    }
}
    
Example 3

public static void method(int n) {
    int sum = 0;
    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= 4; j++) {
            sum++;
        }
    }
}
    
Example 4

public static void method(int n) {
    int sum = 0;
    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= i; j++) {
            sum++;
        }
    }
}
    
Example 5 

// Pre-Condtion: Current is not null
// This algorithm only works for balanced binary trees
public static int countNodes(Node current) {
    if (current.left == null && current.right == null) {  
        return 1;                                        
    } else {
        int leftCount = countNodes(current.left);
        int rightCount = countNodes(current.right);
        return leftCount + rightCount + 1;
    }
}