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?
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
/**
* With Java Streams
* @param first First Array
* @param second Second Array
* @return Merged Array
*/
String[] mergeArrayOfStrings(String[] first, String[] second) {
return Stream.concat(Arrays.stream(first), Arrays.stream(second)).toArray(String[]::new);
}
其他回答
void f(String[] first, String[] second) {
String[] both = new String[first.length+second.length];
for(int i=0;i<first.length;i++)
both[i] = first[i];
for(int i=0;i<second.length;i++)
both[first.length + i] = second[i];
}
这一个在不了解任何其他类/库等的情况下工作。它适用于任何数据类型。只需将String替换为int、double或char等任意值。它的工作效率很高。
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]
/**
* With Java Streams
* @param first First Array
* @param second Second Array
* @return Merged Array
*/
String[] mergeArrayOfStrings(String[] first, String[] second) {
return Stream.concat(Arrays.stream(first), Arrays.stream(second)).toArray(String[]::new);
}
这应该是一个衬垫。
public String [] concatenate (final String array1[], final String array2[])
{
return Stream.concat(Stream.of(array1), Stream.of(array2)).toArray(String[]::new);
}
String [] both = new ArrayList<String>(){{addAll(Arrays.asList(first)); addAll(Arrays.asList(second));}}.toArray(new String[0]);