我需要在Java中连接两个字符串数组。

void f(String[] first, String[] second) {
    String[] both = ???
}

哪种方法最简单?


当前回答

FunctionalJava库有一个数组包装器类,它为数组提供了方便的方法,如串联。

import static fj.data.Array.array;

…然后

Array<String> both = array(first).append(array(second));

要取回展开的数组,请调用

String[] s = both.array();

其他回答

以下是对我有用的:

String[] data=null;
String[] data2=null;
ArrayList<String> data1 = new ArrayList<String>();
for(int i=0; i<2;i++) {
   data2 = input.readLine().split(",");
   data1.addAll(Arrays.asList(data2));
   data= data1.toArray(new String[data1.size()]);
   }

算法爱好者的另一个答案是:

public static String[] mergeArrays(String[] array1, String[] array2) {
    int totalSize = array1.length + array2.length; // Get total size
    String[] merged = new String[totalSize]; // Create new array
    // Loop over the total size
    for (int i = 0; i < totalSize; i++) {
        if (i < array1.length) // If the current position is less than the length of the first array, take value from first array
            merged[i] = array1[i]; // Position in first array is the current position

        else // If current position is equal or greater than the first array, take value from second array.
            merged[i] = array2[i - array1.length]; // Position in second array is current position minus length of first array.
    }

    return merged;

用法:

String[] array1str = new String[]{"a", "b", "c", "d"}; 
String[] array2str = new String[]{"e", "f", "g", "h", "i"};
String[] listTotalstr = mergeArrays(array1str, array2str);
System.out.println(Arrays.toString(listTotalstr));

结果:

[a, b, c, d, e, f, g, h, i]

哇!这里有很多复杂的答案,包括一些依赖于外部依赖的简单答案。这样做怎么样:

String [] arg1 = new String{"a","b","c"};
String [] arg2 = new String{"x","y","z"};

ArrayList<String> temp = new ArrayList<String>();
temp.addAll(Arrays.asList(arg1));
temp.addAll(Arrays.asList(arg2));
String [] concatedArgs = temp.toArray(new String[arg1.length+arg2.length]);

这一个只适用于int,但想法是通用的

public static int[] junta(int[] v, int[] w) {

int[] junta = new int[v.length + w.length];

for (int i = 0; i < v.length; i++) {            
    junta[i] = v[i];
}

for (int j = v.length; j < junta.length; j++) {
    junta[j] = w[j - v.length];
}

仅使用Java自己的API:


String[] join(String[]... arrays) {
  // calculate size of target array
  int size = 0;
  for (String[] array : arrays) {
    size += array.length;
  }

  // create list of appropriate size
  java.util.List list = new java.util.ArrayList(size);

  // add arrays
  for (String[] array : arrays) {
    list.addAll(java.util.Arrays.asList(array));
  }

  // create and return final array
  return list.toArray(new String[size]);
}

现在,这段代码不是最有效的,但它只依赖于标准的java类,而且很容易理解。它适用于任意数量的String[](甚至是零数组)。