Week 2: Methods, strings and lists/17a List length and iterating

size


ArrayList<Integer> numbers = new ArrayList<>();
numbers.add(10);
numbers.add(5);
System.out.println(numbers.size()); //2


for(int i=0; i<5; i++) {
    numbers.add(i);
}
System.out.println(numbers); //[10, 5, 0, 1, 2, 3, 4]


int len = numbers.size();
System.out.println(len); //7
 


Program outputs:
2
[10, 5, 0, 1, 2, 3, 4]
7




==================================

i<numbers.size()



ArrayList<Integer> numbers = new ArrayList<>();
numbers.add(10);
numbers.add(5);
numbers.add(6);
numbers.add(22);
numbers.add(-4);
System.out.println(numbers); //[10, 5, 6, 22, -4]


for (int i=0; i<numbers.size(); i++) {
    numbers.set(i, numbers.get(i) + 1);
}
System.out.println(numbers); //[11, 6, 7, 23, -3]
 

Program outputs:
[10, 5, 6, 22, -4]
[11, 6, 7, 23, -3]







==================================

for loop - iterate through each element



ArrayList<Integer> numbers = new ArrayList<>();
numbers.add(10);
numbers.add(5);
numbers.add(6);
numbers.add(22);
numbers.add(-4);

for (int number : numbers) {
    System.out.println(number);
}
 

Program outputs:

10
5
6
22
-4




==================================

SUM length of ALL words




ArrayList<String> words = new ArrayList<>();
words.add("Lake");
words.add("Swamp");
words.add("Hoe");
words.add("Shovel");


int length = 0;
for (String word : words ) {
    length = length + word.length();
}

System.out.println("Combined length: " + length );
 

Program outputs:
Combined length: 19