java 判断数组的最大值和最小值

写了两个方法，不知道效率咋样

public class ArrayTest03 {
    public static void main(String[] args) {
        int[] a= {2,8,3,4,9,1,5};
        ArrayTest03 at3=new ArrayTest03();
        System.out.println(at3.selectBig(a));
        System.out.println(at3.selectLittle(a));
    }
    
    int selectBig(int[] a) {
        int i=0;
        int flag=a[i];
        while(i<a.length-1) {
            if(flag>a[i+1]) {
                i++;
            }else {
                flag=a[i+1];
                i++;
            }
        }
        return flag;
    }
    
    int selectLittle(int[] a) {
        int i=0;
        int flag=a[i];
        while(i<a.length-1) {
            if(flag<a[i+1]) {
                i++;
            }else {
                flag=a[i+1];
                i++;
            }
        }
        return flag;
    }
    
}