大写或小写单词“Java”中的特定字符
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Uppercase or Lowercase a specific character in a word "Java"
提问by Shah91n
I have look into most of questions but I couldn't find how to uppercase or lowercase specific character inside a word.
我研究了大部分问题，但找不到如何在单词中大写或小写特定字符。
Example:
例子：
String name = "Robert"
What if I would like to make "b" Uppercase and rest lowercase also how to make first letter Uppercase and rest lowercase?
如果我想制作“b”大写和其余小写怎么办？如何制作第一个字母大写和其余小写？
Like "john" >> Output >> "John"...
像“约翰”>>输出>>“约翰”...
I have toUppercase()and toLowercase(). They convert the whole text.
我有toUppercase()和toLowercase()。他们转换整个文本。
Also I tried to include charAtbut never worked with me.
我也试图包括charAt但从未与我合作过。
回答by bhooks
You will need to take your string, take a substring of the specific character or characters you want to capitalize or lowercase, and then build a new string off of it.
您需要获取字符串，获取要大写或小写的特定字符的子字符串，然后从中构建一个新字符串。
Example
例子
String test = "JoHn"; //make the H lowercase
test = test.substring(0,2) + test.substring(2,3).toLowercase() + test.substring(3);
The first substring gets all characters before the desired point, the second gets the desired character and lowercases it, and the final substring gets the rest of the string
第一个子字符串获取所需点之前的所有字符，第二个获取所需字符并将其小写，最后一个子字符串获取字符串的其余部分
回答by Lew Bloch
I wouldn't use 'test.substring(2, 3).toLowerCase()' necessarily. 'Character.valueOf(test.charAt(2)).toUpperCase()' works. Also, the 'test.substring(0, 3)' is wrong; it should be 'test.substring(0, 2)'.
我test.substring(2, 3).toLowerCase()不一定会使用 ' '。' Character.valueOf(test.charAt(2)).toUpperCase()' 工作。此外，“ test.substring(0, 3)”是错误的；它应该是“ test.substring(0, 2)”。
回答by Anthony Raymond
A function that capitalize the first letter
首字母大写的函数
private String capitalize(String str) {
return Character.toUpperCase(str.charAt(0)) + str.substring(1);
}
A function that capitalize an arbitrary letter
将任意字母大写的函数
private String replaceCharWithUpperCase(char letterToCapitalize, String str)
{
return str.replaceAll(letterToCapitalize, Character.toUpperCase(letterToCapitalize));
}
Then you can use the previous functions like that :
然后你可以像这样使用以前的功能：
String a = "JOHN";
a = capitalize(a.toLowerCase());
// now a = John.
String b = "ROBERT";
a = replaceCharWithUpperCase('b', a.toLowerCase());
// now a = roBert.
回答by Abdelhak
You can use toCharArray()to capitalize the first letter like this:
您可以toCharArray()像这样将第一个字母大写：
String name = "robert";
// Convert String to char array.
char[] arr = name.toCharArray();
// Modify first element in array.
arr[0] = Character.toUpperCase(arr[0]);
String str = new String(arr);
System.out.println(str);
Output:
输出：
Robert
And you want to make "b" Uppercase and rest lowercase like this:
并且你想让 "b" 大写，其余小写如下：
// Convert String to char array.
char[] arr2 = name.toCharArray();
// Modify the third element in array.
arr2[2] = Character.toUpperCase(arr2[2]);
String str2 = new String(arr2);
System.out.println(str2);
Output:
输出：
roBert
回答by Pralhad
//Try this...
String str = "Robert";
for (int i = 0; i < str.length(); i++) {
int aChar = str.charAt(i);
// you can directly use character instead of ascii codes
if (aChar == 'b') {
aChar = aChar - 32;
} else if (aChar >= 'A' && aChar <= 'Z') {
aChar += 32 ;
}
System.out.print((char) aChar);
}
/*
Output will be- roBert
/*
输出将是-roBert
*/
*/
