Question

这是我的代码：

package com.example.java;

public class PackageDataTest {

    public static void main(String[] args) {
        PackageData data1 = new PackageData("John Davids");
        System.out.printf("%Number of object created until now is : %d", PackageData.count);
    }
}

class PackageData {

    static int count = 0;
    String name;

    public PackageData(){
        this.name = "";
        ++count;
    }

    public PackageData(String name) {
        this.name = name;
        ++count;
    }

    public int getCount() { return count; }
}

我一直收到以下错误：

“线程中的异常”主“java.util.UnknownFormatConversionException：Conversion ='N'”

Answer 1

％N不是有效的转换格式，％n是换行符。

所以如果你替换下面的代码：

System.out.printf("%nNumber of object created until now is : %d", PackageData.count);

输出将在新行上：

Number of object created until now is : 1

查看此讨论：What's up with Java's "%n" in printf?

java.util.UnknownFormatConversionException：Conversion ='N'

1 个答案: