Java PrintStream 类型中的方法 println(double) 不适用于参数 (String, double)
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The method println(double) in the type PrintStream is not applicable for the arguments (String, double)
提问by user2687163
Here is the code:
这是代码：
import java.util.Scanner;
public class MoviePrices {
public static void main(String[] args) {
Scanner user = new Scanner(System.in);
double adult = 10.50;
double child = 7.50;
System.out.println("How many adult tickets?");
int fnum = user.nextInt();
double aprice = fnum * adult;
System.out.println("The cost of your movie tickets before is ", aprice);
}
}
I am very new to coding and this is a project of mine for school. I am trying to print the variable aprice within that string but I am getting the error in the heading.
我对编码很陌生，这是我的一个学校项目。我试图在该字符串中打印变量 aprice，但在标题中出现错误。
采纳答案by Brian
Instead of this:
取而代之的是：
System.out.println("The cost of your movie tickets before is ", aprice);
Do this:
做这个：
System.out.println("The cost of your movie tickets before is " + aprice);
This is called "concatenation". Read this Java trailfor more info.
这称为“串联”。阅读此 Java 跟踪了解更多信息。
Edit:You could also use formatting via PrintStream.printf. For example:
编辑：您也可以通过PrintStream.printf. 例如：
double aprice = 4.0 / 3.0;
System.out.printf("The cost of your movie tickets before is %f\n", aprice);
Prints:
印刷：
The cost of your movie tickets before is 1.333333
你之前的电影票成本是1.333333
You could even do something like this:
你甚至可以做这样的事情：
double aprice = 4.0 / 3.0;
System.out.printf("The cost of your movie tickets before is $%.2f\n", aprice);
This will print:
这将打印：
The cost of your movie tickets before is $1.33
你之前的电影票成本是 1.33 美元
The %.2fcan be read as "format (the %) as a number (the f) with 2 decimal places (the .2)." The $in front of the %is just for show, btw, it's not part of the format string other than saying "put a $ here". You can find the formatting specs in the Formatterjavadocs.
的%.2f可以读作“格式（的%），其为数字（f）用2位小数（的.2）”。在$前面的在%是作秀，顺便说一句，这不是比说其他格式字符串的一部分，“把这里$”。您可以在Formatterjavadocs 中找到格式规范。
回答by jlordo
you are looking for
你正在寻找
System.out.println("The cost of your movie tickets before is " + aprice);
+concatenates Strings. ,separates method parameters.
+连接字符串。,分隔方法参数。
回答by ThePerson
This will help:
这将有助于：
System.out.println("The cost of your movie tickets before is " + aprice);
The reason is that if you put in a coma, you are sending two different parameters. If you use the line above, you add the double onto your string, and then it sends the parameters as a String rather than a String and a double.
原因是，如果您进入昏迷状态，则会发送两个不同的参数。如果使用上面的行，则将 double 添加到字符串中，然后它将参数作为 String 而不是 String 和 double 发送。
回答by ThePerson
Try this one
试试这个
System.out.println("The cost of your movie tickets before is " + aprice);
And you can also do that:
你也可以这样做：
System.out.printf("The cost of your movie tickets before is %f\n", aprice);
回答by YeLiMs NeEvAn
It occurs when you use ,instead of +i.e:
它发生在您使用,而不是+ie 时：
use this one:
使用这个：
System.out.println ("x value" +x);
instead of
代替
System.out.println ("x value", +x);
