Java Printf 帮助格式化

Question

void catalog()
    {
        System.out.printf("\n%-5s%-5s%-15s%-15s%-6s%-15s%-5d\n",
            "Sno.","B.No.","BOOK-NAME","AUTHOR-NAME","COPIES","PUBLISHER","PRICE");
        for(int i=1;i<53;i++)
            System.out.print("-");
        System.out.println();
        for(int i=0;i<nob;i++)
            System.out.printf("%-5d%-5d%-15s%-15s%-5d%-10s%-10d\n",
                (i+1),bno[i],bname[i],author[i],availcopies[i],publisher[i],price[i]);
        for(int i=1;i<53;i++)
            System.out.print("-");
        System.out.println();
    }

我对在 java 中使用 printf 有这个疑问，所以这是我在使用 printf

时遇到的错误

java.util.MissingFormatArgumentException: Format specifier '%-15s'
    at java.util.Formatter.format(Formatter.java:2519)
    at java.io.PrintStream.format(PrintStream.java:970)
    at java.io.PrintStream.printf(PrintStream.java:871)
    at Library.catalog(LibrarySystem.java:162)
    at LibrarySystem.main(LibrarySystem.java:218)

Answer 1

这个

System.out.printf("\n%-5s%-5s%-15s%-15s%-6s%-15s%-5d\n",
    "Sno.","B.No.","BOOK-NAME","AUTHOR-NAME","COPIES","PUBLISHER","PRICE");

将不起作用，因为最后一个是数字，而您将字符串 "PRICE".

传递给它

您应该为列名称使用不同的格式字符串。

列名称："\n%-5s%-5s%-15s%-15s%-6s%-15s%-5s\n"

Answer 2

换行

System.out.printf("\n%-5s%-5s%-15s%-15s%-6s%-15s%-5d\n",
            "Sno.","B.No.","BOOK-NAME","AUTHOR-NAME","COPIES","PUBLISHER","PRICE");

到

System.out.printf("\n%-5s%-5s%-15s%-15s%-6s%-15s%-5s\n",
            "Sno.","B.No.","BOOK-NAME","AUTHOR-NAME","COPIES","PUBLISHER","PRICE");

因为最后一部分 %-5d\n" 将尝试获取 int 值，但您想打印一个字符串，即 "PRICE"

好好休息

简单的错误

Java Printf 帮助格式化

Java Printf Help in formating

java

printf

bluej