java - java中的空格

Question

Java 中的空格有哪些种类？如果文本包含任何空格，我需要检查我的代码。

我的代码是:

if (text.contains(" ") || text.contains("\t") || text.contains("\r") 
       || text.contains("\n"))   
{  
   //code goes here
}   

我已经知道 \n 、\t 、\r 和 space。

Answer 1

对于非正则表达式的方法，你可以查看Character.isWhitespace对于每个字符。

boolean containsWhitespace(String s) {
    for (int i = 0; i < s.length(); ++i) {
        if (Character.isWhitespace(s.charAt(i)) {
            return true;
        }
    }
    return false;
}

---

Which are the white spaces in Java?

文档指定了 Java 认为什么是空白:

public static boolean isWhitespace(char ch)

Determines if the specified character is white space according to Java. A character is a Java whitespace character if and only if it satisfies one of the following criteria:

• It is a Unicode space character (SPACE_SEPARATOR, LINE_SEPARATOR, or PARAGRAPH_SEPARATOR) but is not also a non-breaking space ('\u00A0', '\u2007', '\u202F').
• It is '\u0009', HORIZONTAL TABULATION.
• It is '\u000A', LINE FEED.
• It is '\u000B', VERTICAL TABULATION.
• It is '\u000C', FORM FEED.
• It is '\u000D', CARRIAGE RETURN.
• It is '\u001C', FILE SEPARATOR.
• It is '\u001D', GROUP SEPARATOR.
• It is '\u001E', RECORD SEPARATOR.
• It is '\u001F', UNIT SEPARATOR.