Java中的单引号和双引号有区别吗？
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Is there a difference between single and double quotes in Java?
提问by pupeno
Is there a difference between single and double quotes in Java?
Java中的单引号和双引号有区别吗？
采纳答案by Yuval Adam
Use single quotes for literal chars, double quotes for literal Strings, like so:
对文字chars使用单引号，对文字s使用双引号String，如下所示：
char c = 'a';
String s = "hello";
They cannot be used any other way around (like in Python, for example).
它们不能以任何其他方式使用（例如在 Python 中）。
回答by VonC
A char is a single UTF-16 character, that is a letter, a digit, a punctuation mark, a tab, a space or something similar.
字符是单个 UTF-16 字符，即字母、数字、标点符号、制表符、空格或类似的东西。
A char literal is either a single one character enclosed in single quote marks like this
字符文字是用单引号括起来的单个字符，如下所示
char myCharacter = 'g';
or an escape sequence, or even a unicode escape sequence:
或转义序列，甚至是 Unicode 转义序列：
char a = '\t'; // Escape sequence: tab
char b = '7' // Escape sequence, octal.
char c = '\u03a9' // Unicode escape sequence.
It is worth noting that Unicode escape sequences are processed very early during compilation and hence using '\u00A' will lead to a compiler error. For special symbols it is better to use escape sequences instead, i.e. '\n' instead of '\u00A' .
值得注意的是，Unicode 转义序列在编译过程中很早就被处理，因此使用 '\u00A' 将导致编译器错误。对于特殊符号，最好使用转义序列，即 '\n' 而不是 '\u00A' 。
Double quotes being for String, you have to use a "double quote escape sequence" (\") inside strings where it would otherwise terminate the string.
For instance:
双引号是 for String，你必须\"在字符串中使用“双引号转义序列”（），否则它会终止字符串。
例如：
System.out.println("And then Jim said, \"Who's at the door?\"");
It isn't necessary to escape the double quote inside single quotes.
The following line is legal in Java:
没有必要在单引号内转义双引号。
以下行在 Java 中是合法的：
char doublequote = '"';
回答by Eddy Bayonne
Let's consider this lines of codes (Java):
让我们考虑这行代码（Java）：
System.out.println("H"+"A"); //HA
System.out.println('H'+'a'); //169
1) First line is concatenation of Hand Athat will result in HA(String literal)
1) 第一行是串联的H，A这将导致HA(String literal)
2) Second we are adding the values of two char that according to the ASCII Table H=72 and a=97 that means that we are adding 72+97it's like ('H'+'a').
2) 其次，我们将根据 ASCII 表H=72 和a=97的两个字符的值相加，这意味着我们将72+97其添加为('H'+'a').
3) Let's consider another case where we would have:
3）让我们考虑另一种情况：
System.out.println("A"+'N');//AN
In this case we are dealing with concatenation of String Aand char Nthat will result in AN.
在这种情况下，我们正在处理 StringA和 char 的连接，N这将导致AN.
回答by Horse_1995
Single quote indicates character and double quote indicates string..
单引号表示字符，双引号表示字符串。
char c='c';
字符 c='c';
'c'-----> c is a character
'c'-----> c 是一个字符
String s="stackoverflow";
字符串 s="stackoverflow";
"stackoverflow"------> stackoverflow is a string(i.e collection if characters)
“stackoverflow”------> stackoverflow 是一个字符串（即集合 if 字符）
