Sorry if this isn't the right. This is my first time posting here. I'm a first year Software student and for the life of me i cannot seem to get this to work. I know its something simple I'm missing but oh well. I tried doing this using methods but again no help. Maybe you guys could help me?
The problem is the code wont let me input after the "Are you a member (Y/N)" writline statement and just keeps giving me an output of 50.
static void Main(string[] args)
{
//Local Variable Declaration//
double rate1 = 10;
double rate2 = 3;
double maxCharge = 50;
double charge;
Console.WriteLine("Enter number of hours (-999 to quit) : ");
int hoursRented = Console.Read();
if (hoursRented >= 3)
{
charge = hoursRented * rate1;
}
else
{
charge = (3 * rate1) + (hoursRented * rate2);
}
if (charge > maxCharge)
{
charge = maxCharge;
}
Console.WriteLine("Are you a member? (Y/N) : ");
int memberStatus = Console.Read();
if (memberStatus.Equals("Y"))
{
charge = (charge * 1 / 10) - charge;
}
Console.WriteLine("Customer Charge : {0} Total Charge To Date : ", charge);
}
The problematic lines are below
Console.WriteLine("Enter number of hours (-999 to quit) : ");
int hoursRented = Console.Read();
if (hoursRented >= 3) {
and
Console.WriteLine("Are you a member? (Y/N) : ");
int memberStatus = Console.Read();
if (memberStatus.Equals("Y")) {
When you call Console.Read(), it reads only characters and returns it as an int. You seem to mistakenly think it will parse the character to an int.
Secondly, think what happens when you provide multiple characters as input to a single Console.Read() call. Interestingly, the remaining characters are read in the subsequent calls. So when you type any number followed by Enter in the first Console.Read it only, reads the first character, the subsequent characters, including the EOLN char are returned in the subsequent calls, instead of prompting you to enter information for the next call.
The fix is easy. Use Console.Readline() and int.parse (or its int.TryParse() variant
Then the corresponding code will look like below
Console.Write("Enter number of hours (-999 to quit) : ");
string hoursRentedStr = Console.ReadLine();
int hoursRented = int.Parse(hoursRentedStr);
if (hoursRented >= 3) {
and
Console.Write("Are you a member? (Y/N) : ");
string memberStatus = Console.ReadLine();
if (memberStatus.Equals("Y")) {
This is because you are just writing:
Console.WriteLine("Are you a member? (Y/N) : ");
and continuing through.
you must do it like this:
Console.WriteLine("Are you a member? (Y/N) : ");
Console.ReadLine();
and then:
int memberStatus = Int.Parse(Console.ReadKey());
your problem is that your are using Console.Read wich returns the ascii code of the next charachter as said by #juharr in the comments. so the solution is too simply replace Read By ReadLine and change your code like this, so that ReadLine wich is a string will be converted to the int value that you want
int hoursRented = int.Parse(Console.ReadLine());
And change your member status to a string to compare it with "Y" easily
string memberStatus = Console.ReadLine();
Note: if you want to validate the input you should use a int.TryParse instead of just a normal parse like I used as it returns a bool so you knows when it fails
Related
{
Console.ForegroundColor= ConsoleColor.Yellow;
Console.BackgroundColor = ConsoleColor.DarkRed;
Console.Clear();
Console.WriteLine("Please enter your name and I will tell you how many letters your name has!");
string name = Console.ReadLine();
Count(name);
Console.WriteLine("Now tell me two numbers and I will multiply them!");
Console.Read();
try
{
Multiply();
}
catch (FormatException)
{
Console.WriteLine("You must enter a number!");
}
}
public static void Count(string name)
{
Console.WriteLine("Your name has {0} letters!", name.Length);
}
public static void Multiply()
{
string firstNum = Console.ReadLine();
string secondNum = Console.ReadLine();
int num = Int32.Parse(firstNum);
int num1 = Int32.Parse(secondNum);
int result = num * num1;
Console.WriteLine("The result is {0}", result);
}
Im a beginner and Im learning about methods so I made this simple code where the user should enter two numbers and I should multiply them, the problem is, whenever I enter two random numbers, I am getting some completely different numbers back no matter if i want to add them, multiply them or something third.
I cannot figure out why the "num1 * num2;" is not giving me a correct number. E.G. 54*19 should give me 1026, but instead its giving me -15.
you need to comment on the Console.Read(); line. this is the main cause.
I have run your code by commenting on the above line and it works as expected for me
Also, you need to handle the scenarios when the user can enter a non-integer input, so you could use int.TryParse for the same.
Also, try to handle the scenario where the integer value is very large and the multiplication of two numbers exceeds the integer max value.
Hello I am trying to figure out why my program is not working, it's supposed to output a program in which department codes would be entered and followed by a prompt to enter a mark and so on until Q is entered. I can't seem to get that part working at all. If anyone could help please I will appreciate it.
// declare variables
char deptCode = ' ';
int count = 0;
double markVal, sum = 0, average = 0.0;
{
Console.WriteLine("Enter a department code: ‘C’ or ‘c’ for Computer Science,‘B’ or ‘b’ for History, ‘P’ or ‘p’ for Physics, or enter ‘Q’ or ‘q’ to quit:");
deptCode = Convert.ToChar(Console.ReadLine());
while (char.ToUpper(deptCode) != 'Q')
do
{
Console.Write("Enter a mark between 0 and 100 => ");
markVal = Convert.ToDouble(Console.ReadLine());
{
Console.WriteLine("Enter a department code: ‘C’ or ‘c’ for Computer Science,‘B’ or ‘b’ for History, ‘P’ or ‘p’ for Physics, or enter ‘Q’ or ‘q’ to quit:");
deptCode = Convert.ToChar(Console.ReadLine());
} while (markVal >= 0 && markVal <= 100);
count++;
average = (double)sum / count;
Console.WriteLine("***Error, Please Enter Valid Mark");
Console.WriteLine("The Average mark for Computer Science Students is {0}", average);
Console.WriteLine("The Average mark for Biology Students is {0}", average);
Console.WriteLine("The Average mark for Physics Students is {0}", average);
Console.ReadLine();
{
I am sympathetic to your dilemma and know it can be challenging to learn coding when you are not familiar with it. So hopefully the suggestions below may help to get you started at least down the right path. At the bottom of this is a basic “shell” but parts are missing and hopefully you will be able to fill in the missing parts.
One idea that you will find very helpful is if you break things down into pieces (methods) that will make things easier to follow and manage. In this particular case, you need to get a handle on the endless loops that you will be creating. From what I can see there would be three (3) possible endless loops that you will need to manage.
An endless loop that lets the user enter any number of discipline marks.
An endless loop when we ask the user which discipline to use
And an endless loop when we ask the user for a Mark between 0 and 100
When I say endless loop I mean that when we ask the user for a Discipline or a Mark… then, the user MUST press the “c”, “b” “p” or “q” character to exit the discipline loop. In addition the user MUST enter a valid double value between 0 and 100 to exit the Mark loop. The first endless loop will run allowing the user to enter multiple disciplines and marks and will not exit until the user presses the q character when selecting a discipline.
And finally when the user presses the ‘q’ character, then we can output the averages.
So to help… I will create two methods for you. One that will represent the endless loop for getting the Mark from the user… i.e.…. a number between 0 and 100. Then a second endless loop method that will get the Discipline from the user… i.e. … ‘c’, ‘b’, ‘p’ or ‘q’… and it may look something like…
private static char GetDisciplineFromUser() {
string userInput;
while (true) {
Console.WriteLine("Enter a department code: ‘C’ for Computer Science,‘B’ for Biology, ‘P’ for Physics, or enter ‘Q’ to quit:");
userInput = Console.ReadLine().ToLower();
if (userInput.Length > 0) {
if (userInput[0] == 'c' || userInput[0] == 'b' ||
userInput[0] == 'p' || userInput[0] == 'q') {
return userInput[0];
}
}
Console.WriteLine("Invalid discipline => " + userInput + " try again.");
}
}
Note… the loop will never end until the user selects the characters ‘c’, ‘b’, ‘p’ or ‘q’. We can guarantee that when we call the method above, ONLY those characters are returned.
Next is the endless loop to get the Mark from the user and may look something like…
private static double GetMarkFromUser() {
string userInput;
while (true) {
Console.WriteLine("Enter a mark between 0 and 100 => ");
userInput = Console.ReadLine().Trim();
if (double.TryParse(userInput, out double mark)) {
if (mark >= 0 && mark <= 100) {
return mark;
}
}
Console.WriteLine("Invalid Mark => " + userInput + " try again.");
}
}
Similar to the previous method, and one difference is we want to make sure that the user enters a valid number between 0 and 100. This is done using a TryParse method and most numeric types have a TryParse method and I highly recommend you get familiar with it when checking for valid numeric input.
These two methods should come in handy and simplify the main code. So your next issue which I will leave to you, is how are you going to store these values? When the user enters a CS 89 mark… how are you going to store this info? In this simple case… six variables may work like…
int totalsCSMarks = 0;
int totalsBiologyMarks = 0;
int totalsPhysicsMarks = 0;
double totalOfAllCSMarks = 0;
double totalOfAllBiologyMarks = 0;
double totalOfAllPhysicsMarks = 0;
Now you have something to store the users input in.
And finally the shell that would work using the methods above and you should see this uncomplicates things a bit in comparison to your current code. Hopefully you should be able to fill in the missing parts. Good Luck.
static void Main(string[] args) {
// you will need some kind of storage for each discipline.. see above...
char currentDiscipline = 'x';
double currentMark;
while (currentDiscipline != 'q') {
currentDiscipline = GetDisciplineFromUser();
if (currentDiscipline != 'q') {
currentMark = GetMarkFromUser();
switch (currentDiscipline) {
case 'c':
// add 1 to total number of CS marks
// add currentMarkValue to the total of CS marks
break;
case 'b':
// add 1 to total number of Biology marks
// add currentMarkValue to the total of Biology marks
break;
default: // <- we know for sure that only p could be left
// add 1 to total number of Physics marks
// add currentMarkValue to the total of Physics marks
break;
}
}
}
Console.WriteLine("Averages ------");
//Console.WriteLine("The Average mark for Computer Science Students is {0}", totalOfAllCSMarks / totalCSMarks);
//Console.WriteLine("The Average mark for Biology Students is {0}", ...);
//Console.WriteLine("The Average mark for Physics Students is {0}", ...);
Console.ReadLine();
}
Quick question how do I use same variable for string input in case and int input in another case. Here is what I mean by that, I have a problem where I need to constantly insert number and then put the addition of those numbers inside another variable. This inserting is inside do while loop, for me to exit the loop and to show the sum of those numbers, I need to type "OK" or "ok". I have a problem where I do not know how to use string variable for int inputs.
Here is my code:
string input= "";
int sum = 0;
do
{
Console.WriteLine("Insert the number or OK (ok) for exit: ");
input = Console.ReadLine();
sum += Convert.ToInt32(input);
// this is where I get the error Input string was not in the correct fromat
} while (input != "OK" && input != "ok");
Console.WriteLine(sum)
If anyone knows how to help me with this, I would gladly appreciate it.
First identify that the user entered integer or not using int.TryParse(), if user entered integer then add it to the sum variable otherwise check the string
do
{
Console.WriteLine("Insert the number or OK (ok) for exit: ");
input = Console.ReadLine();
//This will add number only if user enters integer.
if(int.TryParse(input, out int number)
sum += number
} while (input != "OK" && input != "ok");
You have to test for OK before you try to convert to a number, because OK won't convert to a number
string input= "";
int sum = 0;
while(true)
{
Console.WriteLine("Insert the number or OK (ok) for exit: ");
input = Console.ReadLine();
if("OK".Equals(input, StringComparison.OrdinalIgnoreCase)) //do a case insensitive check. Note that it's acceptable to call methods on constants, and doing a string check this way round cannot throw a NullReferenceException
break;//exit the loop
sum += Convert.ToInt32(input);
}
Console.WriteLine(sum);
You'll still get the error if the user enters input other than OK, that is not convertible to a number, but this is the crux of your current problem. I'll leave dealing with other garbages as an exercise for you...
Good day all, I'm new to C# and currently at the stage of experimenting with if-else statements. Upon declaring variables ageUser, permittedAge, input and running the program, I noticed that the if statement and the resulting output don't seem to match.
int ageUser;
int permittedAge = 18;
int input;
Console.Write("Put in your age: ");
input = Convert.ToInt32(Console.Read());
ageUser = input;
if (ageUser < permittedAge)
{
Console.WriteLine("Sorry you are not permitted to enter this site!");
}
else
{
Console.WriteLine("Welcome");
}
Link To Console Output
You will need to change how you read in the input. Read() reads in a character and does not convert that to int like you think it does. (5 becomes 53 due to its ASCII representation). Use ReadLine instead.
Use the folowing instead.
Console.Write("Put in your age: ");
input = Convert.ToInt32(Console.ReadLine());
ageUser = input;
This question already has answers here:
Console.Read not returning my int32 [duplicate]
(7 answers)
Closed 1 year ago.
I have been trying to use Console.Read() and Console.ReadLine() in C# but have been getting weird results. for example this code
Console.WriteLine("How many students would you like to enter?");
int amount = Console.Read();
Console.WriteLine("{0} {1}", "amount equals", amount);
for (int i=0; i < amount; i++)
{
Console.WriteLine("Input the name of a student");
String StudentName = Console.ReadLine();
Console.WriteLine("the Students name is " + StudentName);
}
has been giving me that amount = 49 when I input 1 for the number of students, and Im not even getting a chance to input a student name.
This because you read a char.
Use appropriate methods like ReadInt32() that takes care of a correct conversion from the read symbol to the type you wish.
The reason why you get 49 is because it's a char code of the '1' symbol, and not it's integer representation.
char code
0 : 48
1 : 49
2: 50
...
9: 57
for example: ReadInt32() can look like this:
public static int ReadInt32(string value){
int val = -1;
if(!int.TryParse(value, out val))
return -1;
return val;
}
and use this like:
int val = ReadInt32(Console.ReadLine());
It Would be really nice to have a possibility to create an extension method, but unfortunately it's not possible to create extension method on static type and Console is a static type.
Try to change your code in this way
int amount;
while(true)
{
Console.WriteLine("How many students would you like to enter?");
string number = Console.ReadLine();
if(Int32.TryParse(number, out amount))
break;
}
Console.WriteLine("{0} {1}", "amount equals", amount);
for (int i=0; i < amount; i++)
{
Console.WriteLine("Input the name of a student");
String StudentName = Console.ReadLine();
Console.WriteLine("the Students name is " + StudentName);
}
Instead to use Read use ReadLine and then check if the user input is really an integer number using Int32.TryParse. If the user doesn't input a valid number repeat the question.
Using Console.Read will limit your input to a single char that need to be converted and checked to be a valid number.
Of course this is a brutal example without any error checking or any kind of safe abort from the loops.
For someone who might still need this:
static void Main(string[] args)
{
Console.WriteLine("How many students would you like to enter?");
var amount = Convert.ToInt32(Console.ReadLine());
Console.WriteLine("{0} {1}", "amount equals", amount);
for (int i = 0; i < amt; i++)
{
Console.WriteLine("Input the name of a student");
String StudentName = Console.ReadLine();
Console.WriteLine("the Students name is " + StudentName);
}
}
you get a character char from read not an int. you will need to make it a string first and parse that as a string. THe implementation could look like the below
Console.WriteLine("How many students would you like to enter?");
var read = Console.ReadLine();
int amount;
if(int.TryParse(read,out amount)) {
Console.WriteLine("{0} {1}", "amount equals", amount);
for (int i=0; i < amount; i++)
{
Console.WriteLine("Input the name of a student");
String StudentName = Console.ReadLine();
Console.WriteLine("the Students name is " + StudentName);
}
}
I've changed it to use readline because readline returns a string an doesn't arbitrarily limits the number of students to 9 (the max number with one digit)
Console.Read() is returning the char code of the character that you enter. You need to use Convert.ToChar(amount); to get the character as a string, and then you will need to do int.Parse() to get the value you're looking for.
Console.Read returns the asci value of the key character that was pressed.
If you use Console.ReadKey().KeyChar you'll get a char that represents the actual character that was pressed.
You can then turn that character to a one character string by using .ToString().
Now that you have a string you can use int.Parse or int.TryParse to turn a string containing entirely numeric characters into an integer.
So putting it all together:
int value;
if (int.TryParse(Console.ReadKey().KeyChar.ToString(), out value))
{
//use `value` here
}
else
{
//they entered a non-numeric key
}
Instead of:
int amount = Console.Read();
try:
int amount = 0;
int.TryParse(Console.ReadLine(), out amount);
Its because You read just character code, so for example typing 11 You will still get 49. You need to read string value and the parse it to int value. With code above in case of bad input You will get 0.
Try this:
int amount = ReadInt32();
or if it doesn't work try this:
int amount = Console.ReadInt32();
or this:
int amount = Convert.ToInt32(Console.Readline());
In this, it will read string then it will convert it into Int32 value.
You can also go here: http://www.java2s.com/Tutorials/CSharp/System.IO/BinaryReader/C_BinaryReader_ReadInt32.htm
If nothing works, please let me know.
Console.WriteLine("How many students would you like to enter?");
string amount = Console.ReadLine();
int amt = Convert.ToInt32(amount);
Console.WriteLine("{0} {1}", "amount equals", amount);
for (int i = 0; i < amt; i++)
{
Console.WriteLine("Input the name of a student");
String StudentName = Console.ReadLine();
Console.WriteLine("the Students name is " + StudentName);
}
//thats it
TL;DR; Enter key in Windows isn't a single character. This fact is at the root of many issues related to Console.Read() method.
Complete Details:
If you run below piece of code on your computer then you can solve lot of mysteries behind Console.Read():
static void Main(string[] args)
{
var c = Console.Read();
Console.WriteLine(c);
c = Console.Read();
Console.WriteLine(c);
}
While running the program, hit the Enter key just once on your keyboard and check the output on console. Below is how it looks:
Interestingly you pressed Enter key just once but it was able to cater to two Read() calls in my code snippet. Enter key in windows emits two characters for a new line character namely carriage return (\r - ASCII code 13) and line feed (\n - ASCII code 10). You can read about it more here in this post - Does Windows carriage return \r\n consist of two characters or one character?