java格式化输出printf

Posted 2023-01-06 风泊月

printf的出现是为了提高代码结果的阅读性

基本语法

以%开头 不同的字母含义不同
%数字字母：代表整个数据的长度

代码示例

一个学生类

class Student
    String name;
    int age;
    double salary;
    double height;

    public Student(String name, int age, double salary, double height) 
        this.name = name;
        this.age = age;
        this.salary = salary;
        this.height = height;
    

    @Override
    public String toString() 
        return "Student" +
                "name='" + name + '\\'' +
                ", age=" + age +
                ", salary=" + salary +
                ", height=" + height +
                '';
    

测试

public class Test 
    public static void main(String[] args) 

        List<Student> list = new ArrayList<>();
        for (int i = 0; i < 20; i++) 
            list.add(new Student("张三"+i+"三",20+i,3.4+i,90+i));
        
        System.out.println("姓名\\t\\t年龄\\t\\t薪水\\t\\t\\t身高");

        for (Student student : list) 
            //%s:接收字符串
            // %4d 接收整数从头开始一共四个字符
            // %8.2f 距离前面内容一共8个字符保留并保留两位小数
            // %12.2f 距离前面内容一共12个字符保留并保留两位小数
            // %n 换行
            System.out.printf("%s '%4d %8.2f %12.2f%n",student.name,student.age,student.salary,student.height);

        
    

输出结果