java我需要帮助在for循环中使用大写这个词，这个词不是用eclipse编写的，而是从txt文件导入的

Question

import java.util.*;
import java.io.*;

public class Cascader {
    public static void main(String args[]) throws IOException {
        Scanner inputfile = new Scanner(new File("name.txt"));
        String name = inputfile.nextLine();
        System.out.println("Reading the name...");
        for(int i = 0; i < name.length(); i++) {
            System.out.println(name.charAt(i));
        }
        inputfile.close();
    }
}

Answer 1

回答您的问题：您可能没有“保存”新字符串。toUpperCase()方法返回一个新字符串，其中每个字符都已改为大写

name.toUpperCase(); // does not do anything to the String in the variable 'name'
String newName = name.toUpperCase(); // if name was 'john', newName will be 'JOHN'
name = name.toUpperCase(); // if name was 'john', name will now be 'JOHN'