passing "a" variable?

Question about the task

Under discussion

I see that the second method is passing variable "a". Where odes that variable come from. Do I need to establish variable a first? It seems that variable a is attributed to the amount of 7000 when I run this. Where is it getting this number from? Line 10? Any help with this would be appreciated. I am able to do all the requirements except the last one.

In the public static void hackSalary(int a) method, increase the salary by 1000 and display the following: "Your salary is: <a+1000> dollars per month."
where <a+1000> is the salary increased by 1000.

Example output for a = 7000:
Your salary is: 8000 dollars per month.

Requirements:

The program should display text on the screen.
The main method should not call System.out.println or System.out.print.
The hackSalary method should not return a result.
The main method should call the hackSalary method only once.
The hackSalary method should increase the input parameter by 1000 and output text to the screen according to the specified template.

package com.codegym.task.task02.task0205; /* Pay raise */ public class Solution { public static void main(String[] args) { hackSalary(7000); } public static void hackSalary(int a) { System.out.print("Your salary is:" + (a + 1000) +" " + "dollars per month."); } }

Comments (6)

Popular
New
Old

You must be signed in to leave a comment

Guadalupe Gagnon

Level 37 , Tampa, United States

12 April 2021, 16:26

First some terminology: Parameter - These are declared in parentheses where the method is declared, and define what needs to be passed to the method from the calling code. Line 13 is where the method is declared and the parameters are: (int a). Just remember parameters are referring to method declaration and will not have an initial value. Argument - are what is passed to the method, in parentheses, from the calling code. The arguments MUST match the method parameters or the code will not compile. On line 10, the 7000 inside parentheses is the argument and it correctly matches the parameter of an int (7000 is an int). Just remember that arguments are referring to calling code. Object Orientated Programming uses classes/objects as a way to break up code for easy debugging and reuse. The way all of these different code aspects communicate with each other is by sending and receiving messages with methods and arguments. That may not make a whole lot of sense right now, but with some practice it will start to. Some rules: All methods MUST include: a return type - if it does not return anything then it requires 'void' as the return type a name - subject to Java's naming rules (must start with a letter; contain only letters, numbers, or underscore; etc) and parameters that are a type and a variable name, separated by commas. If no parameters are needed for the method then you still must include the empty parentheses. When using a method in code, you call the method by name and pass in the arguments that match EXACTLY the method parameters. Not matching will result in an error and the code will not compile. The method can use the arguments inside its code by the variable name specified. In the above code the variable name is 'a'. Whatever argument is passed to that method will become 'a', and the output will reflect that.

Guadalupe Gagnon

Level 37 , Tampa, United States

12 April 2021, 16:31

Example 1:

public class Solution {
    public static void main(String[] args) {
        hackSalary(7000);
        hackSalary(2000);
        hackSalary(1000);
        hackSalary(500);
        hackSalary(17000);
    }

    public static void hackSalary(int a) {
        System.out.print("Your salary is:" + (a + 1000) +" " + "dollars per month.");
    }
}

Example 2:

public class Solution {
    public static void main(String[] args) {
        System.out.print("Your salary is:" + (7000 + 1000) +" " + "dollars per month.");
        System.out.print("Your salary is:" + (2000 + 1000) +" " + "dollars per month.");
        System.out.print("Your salary is:" + (1000 + 1000) +" " + "dollars per month.");
        System.out.print("Your salary is:" + (500 + 1000) +" " + "dollars per month.");
        System.out.print("Your salary is:" + (17000 + 1000) +" " + "dollars per month.");
    }
}

These 2 examples output the same exact results, however the first one has a lot less typing. Another thing, the same bugs exists in both of these (everything is printed on one line and the spacing is off). To fix the first one you just need to adjust the method the one line in the method, to fix the second one you need to adjust every single output line. Imagine a project that had 10 million lines of code (which is as big as Facebook). Would you rather find one method with a bug in it like example 1.... or search 10 million lines of code for every single line that method would have replaced to fix them individually like example 2?

Gellert Varga

Level 23 , Szekesfehervar, Hungary

11 April 2021, 20:38

1) I think the problem is only one missing space char difference in your output opposite to the requirement. Think about the difference between these two outputs: Your salary is: 9000 dollars per month. Your salary is:9000 dollars per month. 2) Line 10 sends the value of 7000 to the hackSalary() method (to the line 13.) - The hackSalary() method in line 13 receives this int value and it will name it to variable 'a'. Now in this method you can start to use the variable 'a', and first this is equal to the received value of 7000. Then you can increase it, etc.

Rica

Level 3 , Manchester, United States

12 April 2021, 12:24

Thank you muchly! I was able to figure it out with your first hint. Question of clarification: So line 10 storing 7000 into hackSalary and line 13 is naming the 7000 an integer of "a"? Or am I understanding this incorrectly?

Timmy Prototype developer at Volvo Cars

12 April 2021, 15:49

Exacly, line 10 is "calling" the function named hackSalary on line 13 that has an int value that needs to be set with the name "a". So you are telling it that from line 10 go down to line 13 with the value 7000 in the variable "a" that is needed by the function.

Gellert Varga

Level 23 , Szekesfehervar, Hungary

12 April 2021, 19:08

I think the others answered everything very carefully:) You can easily try all the example programs at this link: https://www.jdoodle.com/online-java-compiler/ I think it's best if you always try all the code right away.