zoukankan      html  css  js  c++  java
  • 【翻译】Java Array的排名前十方法(Top 10 Methods for Java Arrays)

    这里列举了Java Array 的前十的方法。他们在stackoverflow最大投票的问题。

    The following are top 10 methods for Java Array. They are the most voted questions from stackoverflow.

    0.声明一个数组

    0. Declare an array

    String[] aArray = new String[5];
    String[] bArray = {"a", "b", "c", "d", "e"};
    String[] cArray = {"a", "b", "c", "d", "e"};

     1.打印数组

    1. Print an array in Java

    int[] intArray = {1, 2, 3, 4, 5};
    String intArrayString = Arrays.toString(intArray);
    
    //直接输出Array,输出,内存地址:[I@4554617c
    System.out.println(intArray);
    
    //输出:[1, 2, 3, 4, 5]
    System.out.println(intArrayString);

    2.从数组中转为ArrayList

    2. Create an ArrayList from an array

     String[] stringArray = {"a", "b", "c", "d", "e"};
     ArrayList<String> arrayList = new ArrayList<>(Arrays.asList(stringArray));
    //输出[a, b, c, d, e] System.out.println(arrayList);

    3.判断数组是否含有某值

    3. Check if an array contains a certain value

      String[] stringArray = {"a", "b", "c", "d", "e"};
      boolean b = Arrays.asList(stringArray).contains("a");
     //true System.out.println(b);

    4.连接两个数组

    4. Concatenate two arrays

     //需要导入 org.apache.commons.lang3
     int[] intArray1 = {1, 2, 3, 4, 5};
     int[] intArray2 = {6, 7 , 8, 9, 10};
     int[] combinedIntArray = org.apache.commons.lang3.ArrayUtils.addAll(intArray1, intArray2);
     String arrayString = Arrays.toString(combinedIntArray);
     //[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
     System.out.println(arrayString);

     5.Declare an array inline  --- 不知道这个的作用

    method(new String[]{"a", "b", "c", "d", "e"});

    6.将数组的每个元素取出拼接成字符串

    6. Joins the elements of the provided array into a single String

     String j = org.apache.commons.lang3.StringUtils.join(new String[] { "a", "b", "c" }, ":");
    //a:b:c System.out.println(j);

    7.将ArrayList转换为数组

    7.Covnert an ArrayList to an array

     String[] stringsArray = {"a", "b", "c", "d", "e"};
     ArrayList<String> arrayList = new ArrayList<>(Arrays.asList(stringsArray));
     String[] stringArr = new String[arrayList.size()];
     arrayList.toArray(stringArr);

    8.将数组转换为set

    8. Convert an array to a set

      String[] stringsArray = {"a", "b", "c", "d", "e"};
      Set<String> set = new HashSet<String>(Arrays.asList(stringsArray));
      System.out.println(set);
    

    9.反转一个数组

    9. Reverse an array

     String[] stringsArray = {"a", "b", "c", "d", "e"};
     ArrayUtils.reverse(stringsArray);
     //[e, d, c, b, a]
     System.out.println(Arrays.toString(stringsArray));

    10.移除数组的某个元素

    10. 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));
    

    One more - convert int to byte array

    byte[] bytes = ByteBuffer.allocate(4).putInt(8).array();
     
    for (byte t : bytes) {
       System.out.format("0x%x ", t);
    }
    

     

     
  • 相关阅读:
    《构建之法》第四章 第十七章阅读笔记
    2016012037+小学四则运算练习软件项目报告
    阅读《构建之法》所得与初步思考
    随机产生300个四则运算题
    我与软件工程的相识,相知
    转 如何快速看懂一个大型程序 http://blog.csdn.net/jysg9/article/details/24193181
    SQL Server 存储过程(转)
    sql 视图的作用(转http://www.cup.edu.cn/nic/Programing/database/34943.htm)
    linux性能问题(CPU,内存,磁盘I/O,网络)( 转载)
    qtp测试计划
  • 原文地址:https://www.cnblogs.com/caoRM/p/8793512.html
Copyright © 2011-2022 走看看