22 数组的常用方法
package com.hikvision.java.array; import java.util.ArrayList; import java.util.Arrays; /** 关于数组的常用处理方法 */ public class ArrayUtils { public static void main(String[] args) { initArray(); System.out.println("--------------------------------"); int [] intArray = { 1, 2, 3, 4, 5 }; printArray(intArray); System.out.println("--------------------------------"); String[] cArray=new String[]{"a","b","c","d","e"}; arrayToArrayList(cArray); System.out.println("--------------------------------"); cArray=new String[]{"a","b","c","d","e"}; String contain="a"; checkArrayContainValue(cArray,contain); } /* 声明初始化一个数据 */ public static void initArray(){ String[] aArray=new String[5]; String[] bArray={"a","b","c","d","e"}; String[] cArray=new String[]{"a","b","c","d","e"}; System.out.println(Arrays.asList(aArray)); System.out.println(Arrays.asList(bArray)); System.out.println(cArray); } /** * 在Java中输出一个数组 * @param array */ public static void printArray(int [] array){ System.out.println(array); String arrayString=Arrays.toString(array); System.out.println(arrayString); } /** * 从数组中创建数组列表 * @param array */ public static void arrayToArrayList(String[] array){ ArrayList<String> arrayList=new ArrayList<>(Arrays.asList(array)); System.out.println(arrayList); } /** * 检查数据中是否包含某个值 * @param array * @param value */ public static void checkArrayContainValue(String[] array,String value){ Boolean isContain=Arrays.asList(array).contains(value); System.out.println(isContain); } // 4. 连接两个数组( Concatenate two arrays) // // int[] intArray = { 1, 2, 3, 4, 5 }; // int[] intArray2 = { 6, 7, 8, 9, 10 }; // // Apache Commons Lang library // int[] combinedIntArray = ArrayUtils.addAll(intArray, intArray2); // // 5. 声明一个数组内链(Declare an array inline ) // // method(new String[]{"a", "b", "c", "d", "e"}); // // 6. 将数组元素加入到一个独立的字符串中(Joins the elements of the provided array into a single String) // // // containing the provided list of elements //// Apache common lang // String j = StringUtils.join(new String[] { "a", "b", "c" }, ", "); // System.out.println(j); //// a, b, c // // 7. 将数组列表转换成一个数组 (Covnert an ArrayList to an array) // // String[] stringArray = { "a", "b", "c", "d", "e" }; // ArrayList<String> arrayList = new ArrayList<String>(Arrays.asList(stringArray)); // String[] stringArr = new String[arrayList.size()]; // arrayList.toArray(stringArr); // for (String s : stringArr) // System.out.println(s); // // 8. 将数组转换成一个集合(Convert an array to a set) // // Set<String> set = new HashSet<String>(Arrays.asList(stringArray)); // System.out.println(set); ////[d, e, b, c, a] // // 9. 反向数组(Reverse an array) // // int[] intArray = { 1, 2, 3, 4, 5 }; // ArrayUtils.reverse(intArray); // System.out.println(Arrays.toString(intArray)); ////[5, 4, 3, 2, 1] // // 10. 删除数组元素(Remove element of an array) // // int[] intArray = { 1, 2, 3, 4, 5 }; // int[] removed = ArrayUtils.removeElement(intArray, 3);//create a new array // System.out.println(Arrays.toString(removed)); }
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