Separating a number from a string
Author
I have a string in my program that is like this "jornada1" or "jornada2" and so on
until the user say to stop. My question is if i can separate the numeric part from
the rest so i can get the number 1,2,....,23. I'm using C and yes it is a school project but just a small part of it the rest i can handle :P, and yes i've search on the internet (not very much just a little).
If you look in ctype.h, you'll find the function isalpha(). Just make a loop to look through the string, character by character, till you find an alphanumerical character (or you hit the end of the string). Then use atoi() (in stdlib.h) to convert that number from a string to an integer.
What you want to do, is go and search the string.
Start at the start
Chat* Start
You then keep going until you find something thats between '0' and '9'.
When you do, you add that to the other string (just malloc an array the same size as your origional string. it may waste space, buts its easy to do).
Now, what you should do, is in between numbers, put a space character between them.
So, you need to keep a little bit of state. just a bool to say wether or not we nee dto shove in the space chr.
Whenever you set a number, you set it to true. when your not on a number, and the space bool is true, you set it to false, and you go and add the space to the character.
So, once you've done all that, you add a \0 to the end of the other string, and free the rest of the string.
you end up with something which turns
"Hefawef12324weafnewwa45#Q$#EDAdar*QY#%(#eda352"
into
"12324 45 352"
Thats what you asked for, wasn't it?
I'm not going to give code.
From,
Nice coder
Start at the start
Chat* Start
You then keep going until you find something thats between '0' and '9'.
When you do, you add that to the other string (just malloc an array the same size as your origional string. it may waste space, buts its easy to do).
Now, what you should do, is in between numbers, put a space character between them.
So, you need to keep a little bit of state. just a bool to say wether or not we nee dto shove in the space chr.
Whenever you set a number, you set it to true. when your not on a number, and the space bool is true, you set it to false, and you go and add the space to the character.
So, once you've done all that, you add a \0 to the end of the other string, and free the rest of the string.
you end up with something which turns
"Hefawef12324weafnewwa45#Q$#EDAdar*QY#%(#eda352"
into
"12324 45 352"
Thats what you asked for, wasn't it?
I'm not going to give code.
From,
Nice coder
Following up on the <ctype> hint, there is also defined 'isdigit' which you should use instead of manually looking for the character range '0' to '9'.
If you want to extract the actual number, you'll need to use atoi() (from stdlib.h), passing it the position in the input where the first digit is. (Depending on your situation you may need the more general strtol() instead.)
If you want to extract the actual number, you'll need to use atoi() (from stdlib.h), passing it the position in the input where the first digit is. (Depending on your situation you may need the more general strtol() instead.)
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