（适用于初学者）：输入字符数组，无特定大小。 使用：字符数组。 创建一个实现间隔的条件。 （在C中）

Question

Function that, given a person's name, prints his initials.

1) Can someone please show how to input an array of characters, making the array as long as the user types characters. (LIKE step by step, its super complicated for a beginner, and explain the functions you use) <3 <3

2) Then how to USE that array of characters in a function, loop or to print a character of that string at a certain index.

3) Also can someone please demonstrate how you would make a condition that has an interval as per the below in a loop, ex:

variable < [65-90] <---- how would you formally type it in code

4) Any advice on where to improve the function ?

---

#include <stdio.h>
#include <string.h>
#include <ctype.h>

int giveInitials(void)
    {

    char name[], upperCasedName[];

    name = fgets("Full Name: ");
    uppperCasedName = toupper(name);


    int n, count, i;

    n = strlen(name);
    count = 0;
    i = count;


    while (count < n)
    {
        // While Loop1: iterates until (int) value at index of char array (upperCasedName) = 65-90 (until it gets to the first letter)
        while ((int)upperCasedName[count] != [65-90] )
        {
            for (i = count; i < n ; i++)
            {
                count++;
            }
        }

        printf("%c", upperCasedName[count]);

        // While Loop2: iterates until (int) value at index of char array (upperCasedName) != 65-90 (until it gets to a none-letter)
        while ((int)upperCasedName[count] = [65-90])
        {
            for (i = count; i < n; i++)
            {
                count++;
            }
        }

    } // End of While loop

}

Answer 1

First off, try to read a basic ansi C book first, this is all basic stuff. You sample code looks really weird. C doesn't have 'Strings', it was only arrays, that being said, if your goal is to get initials, a code like the following will make it.

#include <stdio.h>
#include <string.h>
#include <stdlib.h>

int main (int argc, char * argv[])
{

char c;
char initials[1];
int flag1=0;
int counter=0;

while ( (c=getchar()) != EOF )
{
if (counter==0){
initials[0]=c;
printf ("\nFirst char is %c\n", c);
}

if (flag1==1){initials[1]=c;break;}
    if ( c == ' ')
        {
        flag1=1;
        }
counter++;

}
printf ("\nInitials: %s\n", initials); 
}

2. If an array is array[100], you can just walk the array by using an Int variable inside as array[a], where a is 'Int a=0;, then increase a in the function (a++) or point to an specific location, let's say, array[50].

3. variable < [65-90]: If used in a while, you can make something like this.

   while (a>=65 && a<=90) { some code here }

That will limit the actions only when a is between your range.

4. I just gave my advice, strings don't exist! they are just arrays, so... to do things like toupper you have to use a function that will walk your array, converting 1 by 1, you can do this with pointers so you just call the reference and has lower overhead, even though, this program is so little so, don't worry about it.