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Start your free trial###### Adrian Cunanan

**Front End Web Development**Techdegree Student 9,996 Points

# I am trying to build a simple calculator with Ruby. Using Ruby Basic topics. Please help...

Here is my code:

```
# This method greets the user on start up and request their name
# It returns their name
def greeting
name = gets "Hello! Please type your name: "
puts "It is nice to meet you #{name}. I am a simple calculator application. \n
I can add, subtract, multiply, and divide.\n"
return name
end
# This method ask the user what type of calculation they would like to perform
# It returns the operation or an error for erroneous entry
def request_calculation_type
operation_selection = gets "Type 1 to add, 2 to subtract, 3 to multiply, or 4 to divide two numbers: "
if operation_selection == 1
return "add"
elsif operation_selection == 2
return "subtract"
elsif operation_selection == 3
return "multiply"
elsif operation_selection == 4
return "divide"
else return "error"
end
# This method performs the requested calculation
# It returns the result of the calculation
def calculate_answer(operator, a, b)
if operator == "add"
return result= a + b
elsif operator == "subtract"
return result = a - b
elsif operator == "multiply"
return result = a * b
elsif operator == "divide"
return result = a / b
end
name = greeting
run_calculator = 1
while run_calculator == 1
current_calculation = request_calculation_type()
if current_calculation == "error"
puts "I do not understand this type of calculation... Can we try again?"
else
first_number = gets "What is the first number you would you like to #{calc_type}: "
second_numer = gets "What is the second number you would like to #{calc_type}: "
answer = calculate_answer(current_calculation, first_number, second_number)
puts "The answer is #{answer}"
run_calculator = gets "Type 1 to run another calcution or 2 to end: "
end
end
```

Here is the error:

`calculator.rb:69: syntax error, unexpected end-of-input, expecting keyword_end`

FYI - Line 69 is the end in the code

Please help... I would like to accomplish this as my first Ruby program ;-)

## 10 Answers

###### thomascawthorn

22,985 PointsI had a play and had more success with this:

```
# This method greets the user on start up and request their name
# It returns their name
def greeting
puts "Hello! Please type your name: "
name = gets
puts "It is nice to meet you #{name}. I am a simple calculator application. \n
I can add, subtract, multiply, and divide.\n"
name
end
# This method ask the user what type of calculation they would like to perform
# It returns the operation or an error for erroneous entry
def request_calculation_type
puts "Type 1 to add, 2 to subtract, 3 to multiply, or 4 to divide two numbers: "
operation_selection = gets.to_i
if operation_selection == 1
"add"
elsif operation_selection == 2
"subtract"
elsif operation_selection == 3
"multiply"
elsif operation_selection == 4
"divide"
else
"error"
end
end
# This method performs the requested calculation
# It returns the result of the calculation
def calculate_answer(operator, a, b)
if operator == "add"
a + b
elsif operator == "subtract"
a - b
elsif operator == "multiply"
a * b
elsif operator == "divide"
a / b
end
end
name = greeting
run_calculator = 1
while run_calculator == 1
current_calculation = request_calculation_type()
if current_calculation == "error"
puts "I do not understand this type of calculation... Can we try again?"
else
puts "What is the first number you would you like to #{current_calculation}: "
first_number = gets.to_i
puts "What is the second number you would like to #{current_calculation}: "
second_number = gets.to_i
answer = calculate_answer(current_calculation, first_number, second_number)
puts "The answer is #{answer}"
puts "Type 1 to run another calcution or 2 to end: "
run_calculator = gets.to_i
end
end
```

###### thomascawthorn

22,985 PointsLol I literally couldn't help myself. The above code operates as you want it to - I've just added to_i to the gets fucntion.

gets means get string, so if you're relying on a number you need to convert to an integer (to_i)

###### thomascawthorn

22,985 PointsAre you missing an end statement for either of the if statements in "def calculate_answer(operator, a, b)" and "def request_calculation_type"?

```
def calculate_answer(operator, a, b)
if operator == "add"
return result= a + b
elsif operator == "subtract"
return result = a - b
elsif operator == "multiply"
return result = a * b
elsif operator == "divide"
return result = a / b
#missing end?
end
```

###### Daniel Cunningham

21,109 Pointsrequest_calculation_type and calculate_answer need an additional 'end' (1 to end the method, and 1 for the if statements). Additionally, you'll want to add puts or print lines in front of some of your statements (see below). Those lines are not coming up before the gets method is activated.

def greeting puts "Hello! Please type your name: " name = gets

puts "It is nice to meet you #{name}. I am a simple calculator application. \n I can add, subtract, multiply, and divide.\n"

return name

end

###### Adrian Cunanan

**Front End Web Development**Techdegree Student 9,996 Points

Yeah that was it! gets.to_i

Thanks Tom!!!

Here is the edited code:

```
# This method greets the user on start up and request their name
# It returns their name
def greeting
puts "Hello! Please type your name: "
name = gets
puts "It is nice to meet you #{name}"
puts "I am a simple calculator application. I can add, subtract, multiply, and divide."
return name
end
# This method ask the user what type of calculation they would like to perform
# It returns the operation or an error for erroneous entry
def request_calculation_type
puts "Type 1 to add, 2 to subtract, 3 to multiply, or 4 to divide two numbers: "
operation_selection = gets.to_i
if operation_selection == 1
return "add"
elsif operation_selection == 2
return "subtract"
elsif operation_selection == 3
return "multiply"
elsif operation_selection == 4
return "divide"
else
return "error"
end
end
# This method performs the requested calculation
# It returns the result of the calculation
def calculate_answer(operator, a, b)
if operator == "add"
return result= a + b
elsif operator == "subtract"
return result = a - b
elsif operator == "multiply"
return result = a * b
elsif operator == "divide"
return result = a / b
end
end
name = greeting
run_calculator = 1
while run_calculator == 1
current_calculation = request_calculation_type()
if current_calculation == "error"
puts "I do not understand this type of calculation... Can we try again?"
else
puts "What is the first number you would you like to #{current_calculation}: "
first_number = gets.to_i
puts "What is the second number you would like to #{current_calculation}: "
second_number = gets.to_i
answer = calculate_answer(current_calculation, first_number, second_number)
puts "The answer is #{answer}"
puts "Type 1 to run another calculation or 2 to end: "
run_calculator = gets.to_i
if run_calculator != 1
puts "Thanks for working with me to crunch some numbers! See you later ;-)"
end
end
end
```

###### thomascawthorn

22,985 PointsAwesome! If you're as lazy as me, it's handy to remember you don't need to return values with ruby. The last line of the method is automatically returned. You could shorten like so:

```
return result= a + b
```

you can just do

```
a + b
```

and

```
return "multiply"
```

to

```
"multiply"
```

###### thomascawthorn

22,985 PointsHave you looked at both "def calculate_answer(operator, a, b)" and "def request_calculation_type"? *

###### Adrian Cunanan

**Front End Web Development**Techdegree Student 9,996 Points

Yeah i realized that after i wrote that last comment that I then deleted after I read your suggestion for both methods ;-)

###### Adrian Cunanan

**Front End Web Development**Techdegree Student 9,996 Points

Thanks Tom! That resolved the error.

However, the calculator is not working. None of the puts statements seem to output.

Am I calling the methods incorrectly?

###### thomascawthorn

22,985 PointsYour "gets" Syntax needs to be more like: (or atleast - this worked for me)

```
puts "What is your name: "
name = gets
```

###### Kevin Naegele

10,868 Pointsi would like to see this app when it is done.

###### Adrian Cunanan

**Front End Web Development**Techdegree Student 9,996 Points

You can add the code in my last comment to a new Workspace. Nothing fancy... It's ALIVE!!!

###### Adrian Cunanan

**Front End Web Development**Techdegree Student 9,996 Points

Here is a better version with formatting that makes the program easier to read:

```
# This method greets the user on start up and request their name
# It returns their name
def greeting
puts "Hello! Please type your name: "
name = gets
puts "\n" + "It is nice to meet you #{name}"
puts "\n" + "I am a simple calculator application. I can add, subtract, multiply, and divide."
return name
end
# This method ask the user what type of calculation they would like to perform
# It returns the operation or an error for erroneous entry
def request_calculation_type
puts "\n" + "Type 1 to add, 2 to subtract, 3 to multiply, or 4 to divide two numbers: "
operation_selection = gets.to_i
if operation_selection == 1
return "add"
elsif operation_selection == 2
return "subtract"
elsif operation_selection == 3
return "multiply"
elsif operation_selection == 4
return "divide"
else
return "error"
end
end
# This method performs the requested calculation
# It returns the result of the calculation
def calculate_answer(operator, a, b)
if operator == "add"
return a + b
elsif operator == "subtract"
return a - b
elsif operator == "multiply"
return a * b
elsif operator == "divide"
return a / b
end
end
name = greeting
run_calculator = 1
while run_calculator == 1
current_calculation = request_calculation_type()
if current_calculation == "error"
puts "\n" + "I do not understand this type of calculation... Can we try again?"
else
puts "\n" + "What is the first number you would you like to #{current_calculation}: "
first_number = gets.to_i
puts "\n" + "What is the second number you would like to #{current_calculation}: "
second_number = gets.to_i
answer = calculate_answer(current_calculation, first_number, second_number)
puts "\n" + "The answer is #{answer}"
puts "\n" + "Type 1 to run another calculation or anything else to end: "
run_calculator = gets.to_i
if run_calculator != 1
puts "\n" + "Thanks for working with me to crunch some numbers! See you later ;-)"
end
end
end
```

###### Liviu Tudor

7,061 Pointsjust tried this ! is amazing ! thank you

## thomascawthorn

22,985 Points## thomascawthorn

22,985 PointsTo save counting, you might want to add where line 69 is with a comment!