数组的使用

数组使用

• 普通的For循环

  package com.kazesan.array;
  
  import com.sun.scenario.effect.impl.sw.java.JSWBlend_SRC_OUTPeer;
  
  public class ArrayDemo03 {
      public static void main(String[] args) {
          int[] arrays = {1,2,3,4,5};
          //打印全部的数组元素
          for (int i = 0; i < arrays.length; i++) {
              System.out.println(arrays[i]);
          }
          System.out.println("===================");
          //计算所有元素的和
          int sum = 0;
          for (int i = 0; i < arrays.length; i++) {
              sum += arrays[i];//sum=sum+arrays[i]
          }
          System.out.println("sum="+sum);
          System.out.println("===================");
          //查找最大元素
          int max = arrays[0];
  
          for (int i = 1; i < arrays.length; i++) {
              if (arrays[i] > max){
                  max = arrays[i];
              }
          }
          System.out.println("max="+max);
  
      }
  }
  
  

• For-Each循环(增强型)

  public class ArrayDemo04{
      public static void main(String[] args){
          int[] arrays = {1,2,3,4,5};
          for (int array : arrays) {
              System.out.println(array);//12345
          }
      }
  }
  

• 数组作方法入参

  public class ArrayDemo04 {
      public static void main(String[] args) {
      int[] arrays = {1,2,3,4,5};
      printArray(arrays);
  }
      //打印数组元素
          public static void printArray(int[] arrays){
              for (int i = 0; i < arrays.length; i++) {
                  System.out.print(arrays[i] + " ");
                  /*1
                    2
                    3
                    4
                    5*/ 
              }
          }
  }
  
  
  

• 数组作返回值

  public class ArrayDemo04{
      public static void main(String[] args){
          int[] arrays = {1,2,3,4,5};
          int[] reverse = reverse(arrays);
          printArray(reverse);
      }
          //打印数组元素
          public static void printArray(int[] arrays){
              for (int i = 0; i < arrays.length; i++) {
                  System.out.print(arrays[i] + " ");//5 4 3 2 1
              }
          }
  }
      
      //反转数组
          public static int[] reverse(int[] arrays){
          int[] result = new int[arrays.length];
  
          //反转的操作
              for (int i = 0,j=result.length-1;i < arrays.length;i++,j--){
                  result[j] = arrays[i];
              }
              return result;
          }
  }