我使用Java从用户获得一个字符串输入。我试着让输入的第一个字母大写。
我试了一下:
String name;
BufferedReader br = new InputStreamReader(System.in);
String s1 = name.charAt(0).toUppercase());
System.out.println(s1 + name.substring(1));
这导致了以下编译错误:
类型不匹配:不能从InputStreamReader转换为BufferedReader 不能在基本类型char上调用toUppercase()
当前回答
那些谁搜索首字母大写的名字在这里..
public static String capitaliseName(String name) {
String collect[] = name.split(" ");
String returnName = "";
for (int i = 0; i < collect.length; i++) {
collect[i] = collect[i].trim().toLowerCase();
if (collect[i].isEmpty() == false) {
returnName = returnName + collect[i].substring(0, 1).toUpperCase() + collect[i].substring(1) + " ";
}
}
return returnName.trim();
}
usase: capitaliseName(“saurav khan”); 输出:Saurav Khan
其他回答
String str = "java";
String cap = str.substring(0, 1).toUpperCase() + str.substring(1);
// cap = "Java"
用你的例子:
public static void main(String[] args) throws IOException {
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
// Actually use the Reader
String name = br.readLine();
// Don't mistake String object with a Character object
String s1 = name.substring(0, 1).toUpperCase();
String nameCapitalized = s1 + name.substring(1);
System.out.println(nameCapitalized);
}
你可以试试这个
/**
* capitilizeFirst(null) -> ""
* capitilizeFirst("") -> ""
* capitilizeFirst(" ") -> ""
* capitilizeFirst(" df") -> "Df"
* capitilizeFirst("AS") -> "As"
*
* @param str input string
* @return String with the first letter capitalized
*/
public String capitilizeFirst(String str)
{
// assumptions that input parameter is not null is legal, as we use this function in map chain
Function<String, String> capFirst = (String s) -> {
String result = ""; // <-- accumulator
try { result += s.substring(0, 1).toUpperCase(); }
catch (Throwable e) {}
try { result += s.substring(1).toLowerCase(); }
catch (Throwable e) {}
return result;
};
return Optional.ofNullable(str)
.map(String::trim)
.map(capFirst)
.orElse("");
}
你也可以试试这个:
String s1 = br.readLine();
char[] chars = s1.toCharArray();
chars[0] = Character.toUpperCase(chars[0]);
s1= new String(chars);
System.out.println(s1);
这比使用substring更好(优化了)。(但不用担心小弦)
它的效率是101%
public class UpperCase {
public static void main(String [] args) {
String name;
System.out.print("INPUT: ");
Scanner scan = new Scanner(System.in);
name = scan.next();
String upperCase = name.substring(0, 1).toUpperCase() + name.substring(1);
System.out.println("OUTPUT: " + upperCase);
}
}
StringUtils.capitalize(..) from commons-lang
