00-Java数组遍历性能对比

三种遍历方式性能对比

1. 循环与数组的length比较

public class JavaMain {
    static Object[] objs = new Object[10000000];
    static int zero() {
        int sum = 0;
        for(int i = 0; i < objs.length; i++) {
            sum ^= objs[i].hashCode();
        }
        return sum;
    }
}

2. 将数组length存在方法栈中

public class JavaMain {
    static Object[] objs = new Object[10000000];
    static int one() {
        int sum = 0;
        int len = objs.length;
        for(int i = 0; i < len; i++) {
            sum ^= objs[i].hashCode();
        }
        return sum;
    }
}

3. for-each循环