This is a sample of Java's Enhanced For Statement. Get the value of an array or collection in a loop.
Table of Contents
sample | What is the Enhanced For statement? |
Get the value of an array / Get the value of a list | |
Get the key and value of the map | |
Getting out of the loop(break) | |
Return to the top of the loop(continue) |
What is the Enhanced For statement?
for( data type Variable1 : Variables in arrays and collections ){ Process to be executed (using variable 1) } |
- Accesses the values of an array or collection in order.
- It is called an Enhanced For statement because it does not use a variable to count.
Get the value of an array
package test1;
public class Test1 {
public static void main(String[] args) {
int array[] = {1, 2, 3};
for (int i: array){
System.out.println(i); //1 2 3
}
}
}
Line 5 is an array.
Line 7 is an Enhanced For statement to get the value of the array.
Get the value of a list
package test1;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
public class Test1 {
public static void main(String[] args) {
List<String> c = new ArrayList<>(Arrays.asList("one","two","three"));
for (String a : c) {
System.out.println(a); //one two three
}
}
}
Line 8 is a list.
Line 10 is an Enhanced for statement to get the value of the list.
Get the key and value of the map
package test1;
import java.util.HashMap;
import java.util.Map;
public class Test1 {
public static void main(String[] args) {
Map<String,String> color = new HashMap<>();
color.put("a", "one");
color.put("b", "two");
color.put("c", "three");
for (Map.Entry<String, String> c1 : color.entrySet()) {
System.out.println(c1.getKey());// a b c
System.out.println(c1.getValue());//one two three
}
}
}
Line 7 is a map.
Line 12 is an Enhanced for statement.
Lines 13 and 14 get the keys and values of the map.
Getting out of the loop(break)
List<String> c1 = new ArrayList<>(Arrays.asList("red","yellow","blue"));
for (String a : c1) {
if (a == "yellow"){
break;
}
System.out.println(a); // red
}
Line 5 breaks out of the loop of the Enhanced for statement with break.
Only the result "red" will be printed.
Return to the top of the loop(continue)
List<String> c1 = new ArrayList<>(Arrays.asList("red","yellow","blue"));
for (String a : c1) {
if (a == "yellow"){
continue;
}
System.out.println(a); // red blue
}
Line 5 returns to the beginning of the extended for statement (line 3) with continue.
The results "red" and "blue" are output.
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