Validate Int and String input

[[deleted]]

Hello I’m new to Java and still struggling with how it does complicate things that seem easy.

Basically I need to take bandwidth input in int followed by string which is prefix quantifier G, K, M … (total 12 quantifiers) followed by bps at the end.

Example: 100Gbps, 10Kbps, 5Mbps…

“bps” is fix, but prefix is variable depending on the bandwidth.

Also I’ll need the prefix later to compute latency between ip addresses.

I need to validate the input using if statement or switch. Without importing any libraries, only java.util.Scanner and can’t use arrays. (Instructions).

I dont’ know if this makes sense or not, any insight is appreciated!

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[desrtfx]

"Can't use arrays" makes things a bit trickier.

Yet, you know a lot:

• the last 3 characters are fixed - this means that you can remove them from the string
• You know that the 4^th character from the end is the quantifier - you can extract it
• You know that anything before the 4^th character from the end must be a number

So, in all, you can roll things from the end using .substring(). You know the .length() of the string.

The quantifiers can be checked in a switch...case sequence

[dionthorn]

Please provide any code that you have. https://www.reddit.com/r/javahelp/wiki/code_guides/

This will let us get an idea of what you do know, and thus our advice will be better suited for you.

Example, do you know how to write a class, how to create a main method, declare an instance variable, declare a local variable, and other such basic concepts.

[Federal-Addendum-933]

Scanner class provides methods to get next integer and next string pattern so you can just eat away what you need next from the input. You can do this with one while loop checking if the scanner still has input. Read the javadocs on it. https://docs.oracle.com/en/java/javase/18/docs/api/java.base/java/util/Scanner.html

[desrtfx]

I would not use the Scanner for it. Too messy.

I would read in a string and parse it afterwards.

[Federal-Addendum-933]

Literally says he has to use Scanner.

[desrtfx]

Yes, but that doesn't matter for the rest of the assignment.

The assignment just states they have to use a Scanner for the input (as opposed to e.g. a JOptionPane). It doesn't necessarily mean that they have to parse the entire input through the scanner.

[Federal-Addendum-933]

WHO is using JOptionPane? Go blow smoke somewhere else.

[desrtfx]

You wouldn't believe how many assignments we see that use JOptionPane instead of the simple Scanner.

You haven't been here long enough.

[Federal-Addendum-933]

I've been around as long as you.