Is there a difference between single and double quotes in Java?
在Java中单引号和双引号之间有区别吗?
4 个解决方案
#1
122
Use single quotes for literal chars, double quotes for literal Strings, like so:
文字字符使用单引号，文字字符串使用双引号，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)。
#2
30
A char is a single UTF-16 character, that is a letter, a digit, a punctuation mark, a tab, a space or something similar.
字符是一个UTF-16字符，即一个字母、一个数字、一个标点符号、一个标签、一个空格或类似的东西。
A char literal is either a single one character enclosed in single quote marks like this
char文字可以是像这样用单引号括起来的单个字符
char myCharacter = 'g';
or an escape sequence, or even a unicode escape sequence:
或转义序列，甚至unicode转义序列:
char a = '\t'; // Escape sequence: tab
char b = '\177' // 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。对于特殊的符号，最好使用转义序列，例如。'\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:
双引号表示字符串，您必须在字符串内部使用“双引号转义序列”(\)，否则它将终止字符串。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:
没有必要转义单引号中的双引号。以下一行在Java中是合法的:
char doublequote = '"';
#3
6
Let's consider this lines of codes (Java):
让我们考虑一下这几行代码(Java):
System.out.println("H"+"A"); //HA
System.out.println('H'+'a'); //169
1) First line is concatenation of H and A that will result in HA (String literal)
1)第一行是H和A的串联，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+97 it's like ('H'+'a').
2)其次，根据ASCII表H=72和a=97我们添加了两个char的值，这意味着我们添加了72+97，就像('H'+'a')一样。
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 A and char N that will result in AN.
在本例中，我们处理的是字符串A和char的串联，这将导致一个。
#4
1
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是一个字符
String s="*";
字符串s =“*”;
"*"------> * is a string(i.e collection if characters)
“*”——> *是一个字符串(i)。e系列如果字符)
#1
122
Use single quotes for literal chars, double quotes for literal Strings, like so:
文字字符使用单引号，文字字符串使用双引号，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)。
#2
30
A char is a single UTF-16 character, that is a letter, a digit, a punctuation mark, a tab, a space or something similar.
字符是一个UTF-16字符，即一个字母、一个数字、一个标点符号、一个标签、一个空格或类似的东西。
A char literal is either a single one character enclosed in single quote marks like this
char文字可以是像这样用单引号括起来的单个字符
char myCharacter = 'g';
or an escape sequence, or even a unicode escape sequence:
或转义序列，甚至unicode转义序列:
char a = '\t'; // Escape sequence: tab
char b = '\177' // 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。对于特殊的符号，最好使用转义序列，例如。'\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:
双引号表示字符串，您必须在字符串内部使用“双引号转义序列”(\)，否则它将终止字符串。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:
没有必要转义单引号中的双引号。以下一行在Java中是合法的:
char doublequote = '"';
#3
6
Let's consider this lines of codes (Java):
让我们考虑一下这几行代码(Java):
System.out.println("H"+"A"); //HA
System.out.println('H'+'a'); //169
1) First line is concatenation of H and A that will result in HA (String literal)
1)第一行是H和A的串联，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+97 it's like ('H'+'a').
2)其次，根据ASCII表H=72和a=97我们添加了两个char的值，这意味着我们添加了72+97，就像('H'+'a')一样。
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 A and char N that will result in AN.
在本例中，我们处理的是字符串A和char的串联，这将导致一个。
#4
1
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是一个字符
String s="*";
字符串s =“*”;
"*"------> * is a string(i.e collection if characters)
“*”——> *是一个字符串(i)。e系列如果字符)