Java赋值语句的返回值

 public E next() {
            checkForComodification();
            int i = cursor;
            if (i >= size)
                throw new NoSuchElementException();
            Object[] elementData = ArrayList.this.elementData;
            if (i >= elementData.length)
                throw new ConcurrentModificationException();
            cursor = i + 1;
            return (E) elementData[lastRet = i];
        }

public class Test{
	public static void main(String[] args){
      int index=0;
      System.out.println(index =2);
      System.out.println(index);
}

public class Test {
  public Test();
    Code:
       0: aload_0
       1: invokespecial #1                  // Method java/lang/Object."":()V
       4: return
    LineNumberTable:
      line 1: 0
    LocalVariableTable:
      Start  Length  Slot  Name   Signature
          0       5     0  this   LTest;
  public static void main(java.lang.String[]);
    Code:
       0: iconst_0     // 将int类型常量0压入栈  
       1: istore_1     // 弹出栈顶元素0并存入局部变量1（index）
       2: getstatic     #2                  // Field java/lang/System.out:Ljava/io/PrintStream;
       5: iconst_2     // 将int类型常量2压入栈 
       6: dup          // 复制栈顶部一个字长内容
       7: istore_1     // 将int类型的值(复制出的一个字长内容，即常量2)赋值给局部变量1 (index)
       // 调用打印方法打印index 
       8: invokevirtual #3                  // Method java/io/PrintStream.println:(I)V
      11: getstatic     #2                  // Field java/lang/System.out:Ljava/io/PrintStream;
      14: iload_1     // 将局部变量1(index)的值（此时为2）压入栈
      // 调用打印方法打印index 
      15: invokevirtual #3                  // Method java/io/PrintStream.println:(I)V
      18: return
    LineNumberTable:
      line 4: 0
      line 5: 2
      line 7: 11
      line 9: 18