我有一个字符串数组列表(数组列表中的每个单独元素只是一个没有空格的单词),我想获取每个元素并将每个下一个单词附加到字符串的末尾。
所以说数组列表有
element 0 = "hello"
element 1 = "world,"
element 2 = "how"
element 3 = "are"
element 4 = "you?"
我想创建一个名为 sentence 的字符串,其中包含“hello world,你好吗?”
最佳答案
从 Java 8 开始,这已添加到标准 Java API 中:
String.join()
方法:
String joined = String.join("/", "2014", "10", "28" ); // "2014/10/28"
List<String> list = Arrays.asList("foo", "bar", "baz");
joined = String.join(";", list); // "foo;bar;baz"
StringJoiner
也被添加:
StringJoiner joiner = new StringJoiner(",");
joiner.add("foo");
joiner.add("bar");
joiner.add("baz");
String joined = joiner.toString(); // "foo,bar,baz"
此外,它是 nullsafe,对此我表示赞赏。我的意思是,如果 StringJoiner
在 List
中遇到 null
,它不会抛出 NPE:
@Test
public void showNullInStringJoiner() {
StringJoiner joinedErrors = new StringJoiner("|");
List<String> errorList = Arrays.asList("asdf", "bdfs", null, "das");
for (String desc : errorList) {
joinedErrors.add(desc);
}
assertEquals("asdf|bdfs|null|das", joinedErrors.toString());
}
关于java - 字符串的 ArrayList 到一个字符串,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/13695547/