[java基础] java中的自动装箱与自动拆箱

Integer i = 1; //实际上是执行了Integer i = Integer.valueOf(1)

Integer a =1;
int b = a; //自动拆箱就是从对象中把基本数据取出来

Integer a = 100;
Integer b = 100;
System.out.println(a==b); // true

Integer c = 200;
Integer d = 200;
System.out.println(c == d); // false

 public static Integer valueOf(int i) {
	final int offset = 128;
	if (i >= -128 && i <= 127) { // must cache 
	    return IntegerCache.cache[i + offset];
	}
        return new Integer(i);
    }