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
这是算盘常用的密码。
String[] a = {"a", "b", "c"};
String[] b = {"1", "2", "3"};
String[] c = N.concat(a, b); // c = ["a", "b", "c", "1", "2", "3"]
// N.concat(...) is null-safety.
a = null;
c = N.concat(a, b); // c = ["1", "2", "3"]
其他回答
应该会成功的。这是假设String[]第一个,String[]第二个
List<String> myList = new ArrayList<String>(Arrays.asList(first));
myList.addAll(new ArrayList<String>(Arrays.asList(second)));
String[] both = myList.toArray(new String[myList.size()]);
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]);
怎么样:
public String[] combineArray (String[] ... strings) {
List<String> tmpList = new ArrayList<String>();
for (int i = 0; i < strings.length; i++)
tmpList.addAll(Arrays.asList(strings[i]));
return tmpList.toArray(new String[tmpList.size()]);
}
只是想添加,您也可以使用System.arraycopy:
import static java.lang.System.out;
import static java.lang.System.arraycopy;
import java.lang.reflect.Array;
class Playground {
@SuppressWarnings("unchecked")
public static <T>T[] combineArrays(T[] a1, T[] a2) {
T[] result = (T[]) Array.newInstance(a1.getClass().getComponentType(), a1.length+a2.length);
arraycopy(a1,0,result,0,a1.length);
arraycopy(a2,0,result,a1.length,a2.length);
return result;
}
public static void main(String[ ] args) {
String monthsString = "JANFEBMARAPRMAYJUNJULAUGSEPOCTNOVDEC";
String[] months = monthsString.split("(?<=\\G.{3})");
String daysString = "SUNMONTUEWEDTHUFRISAT";
String[] days = daysString.split("(?<=\\G.{3})");
for (String m : months) {
out.println(m);
}
out.println("===");
for (String d : days) {
out.println(d);
}
out.println("===");
String[] results = combineArrays(months, days);
for (String r : results) {
out.println(r);
}
out.println("===");
}
}
Object[] obj = {"hi","there"};
Object[] obj2 ={"im","fine","what abt u"};
Object[] obj3 = new Object[obj.length+obj2.length];
for(int i =0;i<obj3.length;i++)
obj3[i] = (i<obj.length)?obj[i]:obj2[i-obj.length];