int[] num;//声明一个数组
或
int nums[];
num = new int[5];//创建一个数组
arrays.length
计算长度为5的数组{1,2,3,4,5}之和并打印每个数组元素
public class sum {
public static void main(String[] args){
int[] num = new int[5];
for(int i = 1;i<=num.length;i++){
num[i-1]=i;//下标为0开始赋值
System.out.println(num[i-1]);
}
int sum = 0;
for(int j = 0;j<num.length;j++){
sum+= num[j];
}
System.out.print(sum);
}
}
package com.snowMoon;
public class reverse {
public static void main(String[] args) {
int[] arrays = {1, 2, 3, 4, 5};
int[] a = rev(arrays);
printArray(a);
}
public static int[] rev(int[] arrays){
int[] arr = new int[arrays.length];
for (int i = arr.length,j = 0;i>0;i--,j++){
arr[i-1]=arrays[j];
}
return arr;
}
public static void printArray(int[] arrays){
for (int i =0;i<arrays.length;i++){
System.out.println(arrays[i]+" ");
}
}
}
int a[][] = nwe int[][];
public static void main(String[] args){
int[][] arrays = {{1,2},{2,3},{3,4},{4,5}};
for(int i = 0;i<arrays.length;i++){
for(int j = 0;j<arrays[i].length;j++){
System.out.print(arrays[i][j]);
}
}
}
java.util.Arrays
public class Sort {
public static void main(String[] args) {
int[] a = {99,88,777,8556,123,12,5,100};
int[] arr = sort(a);
System.out.println(Arrays.toString(arr));
}
public static int[] sort(int[] arrays){
int max = 0;
boolean flag = false;//优化时间复杂度
for (int i = 0;i< arrays.length-1;i++){
for (int j = 0;j<arrays.length-1-i;j++){
if (arrays[j+1]>arrays[j]){//从大到小>,从小到大<
max = arrays[j+1];
arrays[j+1] = arrays[j];
arrays[j] = max;
flag = true;
}
}
if (flag == false){
break;
}//优化时间复杂度
}
return arrays;
}
}
............
原文:https://www.cnblogs.com/snowMoon/p/14998248.html