能举例说明java format的用法吗

?????Java??String.format()??????????????????,????????????????????????????????String.format()?????:

1. ?????:

String name = "Alice";
int age = 30;
String formattedString = String.format("My name is %s and I am %d years old.", name, age);
System.out.println(formattedString);

??:

My name is Alice and I am 30 years old.

2. ???????:

double pi = 3.141592653589793;
String formattedPi = String.format("Pi is approximately %.2f", pi);
System.out.println(formattedPi);

??:

Pi is approximately 3.14

??????,%.2f?????????????????????

3. ??????:

String.format()?????????????????,?????%d??????,%f???????,%s?????????

int daysOfWeek = 7;
String days = String.format("d", daysOfWeek); // ??0??????
System.out.println(days); // ??: 07

??????,d??????????????????,??????,??0???

4. ???????:

?Java 5??,?????????????????????????????????????

String name = "Alice";
int age = 30;
String formattedString = String.format("My name is %s and I am %d years old.", name, age);
System.out.println(formattedString);

// ???????
formattedString = String.format("My name is {name} and I am {age} years old.", name=name, age=age);
System.out.println(formattedString);

??:????????????,?????????????????????????,??Java?String.format()???????????????,??????Java 5????????Map?????????????

??????????(??Map):

import java.util.HashMap;
import java.util.Map;

public class Main {
    public static void main(String[] args) {
        String name = "Alice";
        int age = 30;
        Map values = new HashMap<>();
        values.put("name", name);
        values.put("age", age);
        
        String formattedString = String.format("My name is %s and I am %d years old.", name, age);
        System.out.println(formattedString);
        
        formattedString = String.format("My name is {name} and I am {age} years old.", values);
        System.out.println(formattedString);
    }
}

??:

My name is Alice and I am 30 years old.
My name is {name} and I am {age} years old.

??????????,???????Map???????????????,??????{name}?{age}?????????