A quick question about strings . . .

[Nyrd]

I was told by my teacher that strings are essentially arrays of string(1).
This makes sense, because we can compare each individual character and such right?

code:

if string1(1) < string 2(1) then . . .

The problem is that when I try assigning each individual character a new value,

code:

var it : string := "bob" it(1) := a

it pops up with an error saying that "the left side of the assignment is not a variable and hence cannot be assigned to "
why does this happen?

[Mackie]

It is an array but, not exactly like the array's you make. They can only be used for reference, not assignment.


Try something like this.

code:

var word : string := "bob" word := "a" + word (2..3)

It's a pain.

[Nyrd]

Hmmm . . . Pain indeed

Is there any relatively efficient way to make that work such that I could replace any character, or am I just better off creating an actual array?

[Mackie]

Ah well it depends what you want to use it for.

[Nyrd]

Never mind, after a bit of tinkering that way can be made to work pretty well.
Here's what I came up with if anyone is interested

Turing:

var word : string := "oooo" var replacement :string := "x" var num :=1  %Where the replacement character is to go word :=  word (1..num-1) +replacement + word (num+1..length(word)) put word

[Nyrd]

I was actually meaning to use it for a code breaking program. What I came up with above seems to fit my purposes though. Thanks anyway!

[Mackie]

No problem. It's good that you took the time to figure it out on your own. We don't see a lot of that around here.

[Nyrd]

Anything to help you help me!

[Tony]

Nyrd @ Thu Feb 14, 2008 9:24 pm wrote:

... + word (num+1..length(word))

I'm not sure if this works, but I think in Turing you can also do things like

Turing:

word(num .. *)

and even

Turing:

word(num .. * - 1)

It's just syntactical sugar though.

Also -- does your code work when word := "o" ? (I don't have Turing accessible at the moment)

[ericfourfour]

When dealing with strings the * operator means end (or length of the string). It is read as an integer so you can do arithmetic with it. What Tony suggested will work.

If num exceeds the length of word, it will crash. You should put in an if statement that verifies num is in range.