前言：昨天学习的内容没有保存的我哭了，今天去确实是第三天。
数组的定义
public class ArrayDemo {

public static void main(String args[]){
    int data[] = new int [] {1,2,3,4,5};
    for ( int x = 0;x < data.length;x++){
        System.out.println(data[x]);
    }
    for ( int temp : data) { //不会出现先数组越界
        System.out.println(temp);
    }
}

}

数组操作

class Arrrayutils{
    private int sum;
    private double avg;
    private int max;
    private int min;
    public Arrrayutils(int data[]){
        this.max = data[0];
        this.min = data[0];
        for (int x = 0;x<data.length;x++){
            if (data[x]>max){
                this.max = data[x];
            }
            if (data[x]<min){
                this.min = data[x];
            }
            this.sum += data[x];
        }
        this.avg = this.sum/data.length;
    }
    public int getSum(){
        return this.sum ;
    }
    public double getAvg(){
        return this.avg ;
    }
    public int getMin(){
        return this.min ;
    }
    public int getMax(){
        return this.max ;
    }
    }
}

public class ArrayDemo1{
    public static void main(String arg[]){
        int data[] = new int[]{1,2,3,4,5};
        Arrrayutils util = new Arrrayutils(data);//数据计算
        System.out.println("总和"+util.getSum());
        System.out.println("平均"+util.getAvg());
        System.out.println("最大"+util.getMax());
        System.out.println("最小"+util.getMin());
    }
}

数组排序

public static void sort(int data[]){
    for (int x = 0;x<data.length;x++) {
        for (int y = 0; y < data.length - 1; y++) {
            if (data[y] > data[y + 1]) {
                int temp = data[y];
                data[y] = data[y + 1];
                data[y + 1] = temp;
            }
        }
    }

数组转置

public static void reverse(int data[]){
    int center = data.length / 2;
    int head  = 0;
    int tail = data.length-1;
    for (int x = 0;x <center ;x++){
        int temp = data[head];
        data[head] = data[tail];
        data[tail] = temp;
        head++;
        tail--;
    }}

**简单排序：冒泡排序、选择排序、插入排序
高级排序：快速排序、归并排序、希尔排序
相关算法知识：划分、递归、二分查找**