counting characters (1 Viewer)

[untouchablecuz]

hey guys. i'm not sure how to solve this and if anyone could give me a leg up it would awesome (i don't actually WANT the code for the task, just a tip or something)

what i want to do is identify the number of characters that are inputted into scanf(). what i CAN do is identify the number of numbers etc that are inputted (using x=x+1 type of thing), but that doesnt help me

i.e. i want this:

i want the user to input 17 characters into the program

output: system prints you have inputted 17 characters

in terms of code:

scanf("something something", &something)

if (the number of characters inputted equals to 17) {
printf("17 characters inputted");
} else if (the number of characters inputted equals to 18) {
printf("18 characters inputted");
} else {
printf("Not 18 or 17 characters inputted);
}

in general, how do i count the number of characters inputted?

e.g. system Please enter a random number:

user: 456789

system: This number has 7 characters

(edit: sorry if im abit jumbled up)

 

[LordPc]

the answer is really simple and its got nothing to do with program flow or logic, just the syntax of how to print a variable to the screen which i would bet you will learn in the next lecture

anyway, heres the explanation. i assume you are familiar with scanf already.

scanf("%d\n", &exampleVariableName);

the %d incidates that scanf is looking for an integer (d is for decimal. printf works in a very similar way

printf("you entered %d\n", exampleVariableName);

printf will replace the %d with the value of exampleVariableName. note that scanf and printf are very similar but not identical, there is no & in the printf statement

i trust that you can now see how you can replace multiple if statements with a single printf statement

 

[untouchablecuz]

hmm, i already know all that. i don't think you get me

what i mean is:

for example,

scanf("%d\n", &num)

if ([B]num is composed of 7 characters[/B]){
       x=x+1;
} else if ([B]num is composed of 8 characters[/B]) {
       x=2x;
} else {
       x=x%2;
}

understand what i'm getting at? i just used printf functions as an example, anything could replace them. i just need a way of translating the guards into code so that the system can make a choice depending upon the user input

thanks LordPc

 

[acmilan]

Theres a few ways to do it if im understanding your problem. For example:

I'm assuming by number you mean integer, so:
A number has 7 characters if it is > 999999 and < 10000000
A number has 8 characters if its > 9999999 and < 100000000
etc

It's probably not the nicest way to do it but it should work unless im reading your problem wrong.

Another thing you could look at is the getchar() function, strlen() etc.

You could convert the input to a number and constantly divide by 10 until the answer is <1. However many times youve divided by 10 is how many characters the number has. Eg 16346 divided by 10 becomes 1634.6, then 163.46, then 16.345, then 1.6345, then 0.16345. So it took 5 goes to get it <1, so it has 5 characters.

 

[LordPc]

Theres a few ways to do it if im understanding your problem. For example:

I'm assuming by number you mean integer, so:
A number has 7 characters if it is > 999999 and < 10000000
A number has 8 characters if its > 9999999 and < 100000000
etc

It's probably not the nicest way to do it but it should work unless im reading your problem wrong.

Another thing you could look at is the getchar() function, strlen() etc.

You could convert the input to a number and constantly divide by 10 until the answer is <1. However many times youve divided by 10 is how many characters the number has. Eg 16346 divided by 10 becomes 1634.6, then 163.46, then 16.345, then 1.6345, then 0.16345. So it took 5 goes to get it <1, so it has 5 characters.

ok, i dont understand the problem that OP. is it with the syntax of using an if statement? like

scanf("%d\n", &num)

if (num > 7){
       //do something
} else if (num > 8) {
       //do something
} else {
       //do something
}

or do you want some help in creating a way of counting characters in c? like if they enter any number of characters, you want to tell them how many they entered? (type wc -m into a unix terminal, hit enter, type some letters and hit enter again. you will get a number. is this what you want to be able to do?)

otherwise i hope acmilan answered your question cause im stumped

 

[untouchablecuz]

acmilan answered it perfectly funnily enough, i thought of that exact same solution in my comp tute today

thanks for the help fellas

 

[youngmin]

If this is for the COMP1917 assignment, scanf will fail at stage 5.
Obviously that's not a problem if you're COMP1911.

 

[untouchablecuz]

If this is for the COMP1917 assignment, scanf will fail at stage 5.
Obviously that's not a problem if you're COMP1911.

nah COMP1911

and yer i figured, but how else can you input numbers without using scanf? :S

 

[youngmin]

There's this thing called getchar and putchar, we're learning it now. It's more complicated than scanf but yeah, can't do stage 5 without it

 

[untouchablecuz]

There's this thing called getchar and putchar, we're learning it now. It's more complicated than scanf but yeah, can't do stage 5 without it

ah that makes sense

you enjoying comp?

 

[youngmin]

Ahaha yeah, COMP1917 is my favourite subject.
I've barely studied my other ones

You?

 

[untouchablecuz]

Ahaha yeah, COMP1917 is my favourite subject.
I've barely studied my other ones

You?

i came into uni dreading programming. its pretty fun! : D

 

[Prosper]

Just wait 'til you do strings, you'll never want to use putchar/getchar again

 

[appletoa]

Just wait 'til you do strings, you'll never want to use putchar/getchar again

Yeah, that's pretty much what my tutor said. Suppose there could be a bit of an advantage in knowing how to use the basic commands though, in that you get a little more insight into how to use C. Helpful for people who've never programmed before, or people (like me) who haven't programmed in C before.