Java配列よくある使い方

int [] a;
String [] b;
MyClass [] c;

int [] a = new int[3];
String [] b = new String[4];
MyClass [] c = new MyClass[5];    //MyClassは任意のクラス

//int [] a = new int[3];
a[0] = 1;
a[1] = 2;
a[3] = 4;

//String [] b = new String[4];
b[0] = "hello";
b[1] = "world";
...

//MyClass [] c = new MyClass[5];
c[0] = new MyClass();
c[1] = new MyClass("何らかのパラメータ");
...

//int [] a = new int[3];
int value1 = a[0];
int value2 = a[1];

//String [] b = new String[4];
String value3 = b[3];

//MyClass [] c = new MyClass[5];
MyClass value4 = c[4];

public class TestArray {

    /**
     * Java配列のよくある使い方
     */
    public static void main(String[] args) {
        int [] a = new int[3];
        String [] b = new String[4];
        //MyClass [] c = new MyClass[5];
        
        for (int i=0; i<a.length; i++) {
            a[i] = i;
        }
        
        b[0] = "Hello ";
        b[1] = "world ";
        
        System.out.println("****************");
        System.out.println("a.length=" + a.length);
        System.out.println("a[0]=" + a[0]);
        System.out.println("a[1]=" + a[1]);
        System.out.println("a[2]=" + a[2]);
        
        System.out.println("****************");
        System.out.println("b.length=" + b.length);
        System.out.println("b[0]=" + b[0]);
        System.out.println("b[1]=" + b[1]);
        System.out.println("b[2]=" + b[2]);
        System.out.println("b[3]=" + b[3]);
        
        System.out.println("****************");
        System.out.println("for (String value : b)");
        for (String value : b) {// for (int i=0; i<b.length; i++) { String value = b[i];
            System.out.println(value);
        }
    }
}