Caesars Cipher Algorithm, what is wrong with my code?

1

Hi,

I hope some can help me understand what is going on with my code.

I ma trying to solve the Caesar’s Cipher algorithm, and code seems to work for individual letters and also for couple of “opposite” letters.

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But when testing it for something else the results are just weird, returning red and / or wrong letters.

Many thanks for any help out there.

2

The first issue I see is the for loop structure, I think what you are trying to achieve is a “while” loop using a “for” loop. I’m not saying use a while loop but just look at the syntax and structure first and move forward from there.

for (var i=0;i<str.length;i++) {}

this should be your for-loop to help you get on track

3

His way may look odd, but is equivalent. Nothing will change in the operation.

4

Try to step through your algorithm with a string that is failing. You could use a debugger, but it’s easier to just console.log what you got as input and what you replaced it with (at i, str, newstr). In each loop iteration.

1 Like
5

You are doing so many un necessary conditions.
Here’s a few tips to solve the problem.

  1. You need to loop through all the letters inside the string.
    so it’s alright to use for(i=0;i<str.length;i++)
  2. You only need to change the letters between A-Z which are from 65-90. Make a single if statement equivalent to that.
  3. Inside the if statement. Add a certain value to the number equivalent of the letter.
    4.if it becomes >90 add the excess to 64
6

Many thanks for all replies. I have tried different solutions and got one working.

Will do some testing as suggested by lynxlynxlynx and see if I can find out what’s wrong with the code I posted.