java - 检查字符串是否包含\n Java

Question

如何检查字符串是否包含\n 或换行符？

word.contains("\\n")
word.contains("\n")

Answer 1

如果字符串是在同一个程序中构建的，我会推荐使用这个:

String newline = System.getProperty("line.separator");
boolean hasNewline = word.contains(newline);

但是如果你被指定使用\n，这个驱动程序说明了如何做:

class NewLineTest {
    public static void main(String[] args) {
        String hasNewline = "this has a newline\n.";
        String noNewline = "this doesn't";

        System.out.println(hasNewline.contains("\n"));
        System.out.println(hasNewline.contains("\\n"));
        System.out.println(noNewline.contains("\n"));
        System.out.println(noNewline.contains("\\n"));

    }

}

结果

true
false
false
false

回应您的评论:

class NewLineTest {
    public static void main(String[] args) {
        String word = "test\n.";
        System.out.println(word.length());
        System.out.println(word);
        word = word.replace("\n","\n ");
        System.out.println(word.length());
        System.out.println(word);

    }

}

结果

6
test
.
7
test
 .