Java基础系列(38)- 数组的使用
数组的使用
- For-Each循环
- 数组作方法入参
- 数组作返回值
For-Each循环
普通型
package array; import sun.security.util.Length; public class Demo03 { public static void main(String[] args) { int[] a = {1,2,10,4,5}; //遍历打印 for (int i = 0; i < a.length; i++) { System.out.println(a[i]); } System.out.println("==========="); //数组求和 int sum=0; for (int i = 0; i < a.length; i++) { sum+=a[i]; } System.out.println("sum="+sum); System.out.println("==========="); //打印最大元素 int num1 = 0; for (int i = 0; i < a.length; i++) { if (a[i]>num1){ num1 = a[i]; } } System.out.println("max="+num1); } }
增加型
package array; public class Demo04 { public static void main(String[] args) { int[] a = {1,2,10,3,4}; for (int i : a) { System.out.println(i); } } }
数组作方法入参
package array; public class Demo05 { public static void main(String[] args) { int[] a = {1,2,3,4,5}; printArray(a); } public static void printArray(int[] arrays){ for (int i = 0; i < arrays.length; i++) { System.out.print(arrays[i]+" "); } } }
数组作返回值
package array; public class Demo06 { public static void main(String[] args) { int[] a = {1,2,3,4,5}; int[] reverse = reverse(a); printArray(reverse); } //反转数组里面内容 public static int[] reverse(int[] arrays){ int[] results = new int[arrays.length]; for (int i = 0,j = arrays.length-1; i < arrays.length; i++,j--) { results[j]=arrays[i]; } return results; } public static void printArray(int[] arrays){ for (int i = 0; i < arrays.length; i++) { System.out.print(arrays[i]+" "); } } }