Loops / N times
Use for loop when you know how many times you want to loop.
/**
* For Loop, when you know how many loops
* Enhanced For Loop, index not needed
* ForEach, loop over a Collection, ofthen used with ...
* lambdas or method reference
*/
package com.minte9.basics.loops;
import java.util.Arrays;
import java.util.List;
public class Loops {
public static void main(String[] args) {
for (int i=0; i<3; i++) {
System.out.println(i); // 0 1 2
}
int[] nums = {10, 20, 30};
for (int no : nums) {
System.out.println(no); // 10 20 30
}
List<Integer> data = Arrays.asList(100, 200, 300);
data.forEach(x -> System.out.println(x)); // 100 200 300
data.forEach(System.out::println); // 100 200 300
}
}
Break
Use labels to exit from multiple loops.
/**
* Break statement, to exit from a loop
* For multiple loops use labels
*/
package com.minte9.basics.loops;
public class Break {
public static void main(String[] args) {
int[][] numbers = {
{1,2,8},
{4,5,6},
{7,8,9},
};
A: for (int i=0; i<numbers.length; i++) {
B: for (int j=0; j<numbers[i].length; j++) {
System.out.print(i + ":" + j + " ");
if (numbers[i][j] == 4) {
System.out.println("Break from B");
break B;
}
if (numbers[i][j] == 7) {
System.out.println("Break from A");
break A;
}
// 0:0 0:1 0:2 1:0 Break from B
// 2:0 Break from A
}
}
}
}
Last update: 595 days ago
