java - 如何在Java中将String的第一个字母大写？

Question

我正在使用 Java 从用户那里获取 String 输入。我正在尝试将此输入的第一个字母大写。

我试过了:

String name;

BufferedReader br = new InputStreamReader(System.in);

String s1 = name.charAt(0).toUppercase());

System.out.println(s1 + name.substring(1));

导致这些编译器错误:

• Type mismatch: cannot convert from InputStreamReader to BufferedReader

• Cannot invoke toUppercase() on the primitive type char

Answer 1

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);
}