Problem Statement

Did you know that the first six digits of the credit card number encode the card type/issuer? For

example, Visa credit cards in the US begin with the number 4. Although the mapping is a little more sophisticated, for lab 2, write a program that determines the type of credit for an input account number using the following list:

Card Type	Card Number Prefix
American Express	34,37
Discover	65
MasterCard	50-55
Visa	40-49

Write a program that prompts for the account number. Parse off the first two digits. Use the

if-statement to determine the type of credit card. Your program should work on all test cases.

Requirements:

1.Create a script named HW2_yourname.m

2. Follow the algorithm to implement your program.

3. Instead of comparing the prefix as character string, convert and compare the extracted prefix as numbers.

Input Data:

Credit card number, read in as character array

Output Data:

Credit card number and type of credit card

Algorithm:

*Step 1~2 are the same as Lab #2.

Begin you program with clc; clear;

Prompt the user for a 16 digits credit card number.

Determine if the account number is exactly 16 digits. If it is, parse off the first 2 digits. Else output an error message: Invalid card number.

*Hint: 1. Read in the account number as a character array using input() function.

2. Get the length of a string using length() function.

3. Extract first two digits with digits=str(1:2);

4. Convert the extracted digits to a number with str2num();

*Note: For this assignment, you are NOT allowed to use strcmp() function. Compare the extracted digits as a number can greatly reduce the complexity of the logical expressions in if-statement.

Use another set of if-statement to determine the type of credit card. If the credit card type is not in the list, output an error message: Unknown card type.

Use AND(&&), OR(||) operators to evaluate multiple logical expressions at the same time.

Use only one fprintf() function to output the results.

Sample outputs:

Test cases:

Account #	Credit card type
6555160016001600	Discover
5455160016001600	MasterCard
7700160016001600	Unknown
54551234123412341234	Invalid
4555160016001600	Visa

Bonus point:

1. Identify 4A~4Z as Visa Premium card type.

e.g 4X00111122223333, is valid, the card type is Visa Premium.

2. Again, You are not allowed to use the strcmp() function.

Notes

Before each significant step, provide a comment explaining the step (do not comment every line of code). e.g %Extract first two digits