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macOS How can I do this?
- Thread starter seriypshick
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Yes but that would only work with 1 digit number. How can i make it work with 2 or more digits?durvivor said:
Divide the number. First devide by say 1000, and discard the remainder (there is a function in C that does this at least) and apply the switch rule to it. Then take the remainder and divide again by 100 and repeat.
This could have some typos, and it's plain C, no Objective C is used. Make sure you understand everything as I assume you want to learn this. Feel free to ask if you have any questions.
Code:
#include <stdio.h>
int main (int argc, const char *argv[]) {
char ch;
char buffer[256];
int bufferIndex;
// loop and read new numbers until the user enters an empty line
printf("Hit Enter twice to quit\n");
do {
bufferIndex = 0;
// read a number
printf("Enter a number: ");
while (bufferIndex < 255 && (ch = getchar()) != '\n') {
buffer[bufferIndex] = ch;
bufferIndex++;
}
buffer[bufferIndex] = 0;
// write back the digits in plain English
bufferIndex = 0;
while (buffer[bufferIndex] != 0) {
switch (buffer[bufferIndex]) {
case '0':
printf("zero ");
break;
case '1':
printf("one ");
break;
// and so on until '9'
bufferIndex++;
}
printf("\n");
} while (bufferIndex > 0);
return 0;
}
Here's a version in C that takes the input from the command line. So in a terminal window (shell) you can type "showdigits 49971" and it will output the line "four nine nine seven one". (49971 is your member number.)
Here's the program:
Here's the program:
Code:
/* showdigits.c - by Doctor Q */
#include <stdio.h>
main(int argc, char *argv[]) {
char *mypointer ;
if ( argc > 1 ) {
for ( mypointer = argv[1] ; *mypointer != '\0' ; ++mypointer )
switch(*mypointer) {
case '0': printf("zero ") ; break ;
case '1': printf("one ") ; break ;
case '2': printf("two ") ; break ;
case '3': printf("three ") ; break ;
case '4': printf("four ") ; break ;
case '5': printf("five ") ; break ;
case '6': printf("six ") ; break ;
case '7': printf("seven ") ; break ;
case '8': printf("eight ") ; break ;
case '9': printf("nine ") ; break ;
}
printf("\n") ;
}
return 0 ;
}Thanks, everyone.
However, in the book that I'm reading(Programming in Objective-C) author(Stephen Kochan) assumes that previous example would be possible without the use of arrays. (I'm reading 6th chapter, and arrays are introduced in 13th chapter).
Is it at all possible?
Because I also know C I was thinking the same thing. I also think this is the most natural way of doing it.gekko513 said:
However, in the book that I'm reading(Programming in Objective-C) author(Stephen Kochan) assumes that previous example would be possible without the use of arrays. (I'm reading 6th chapter, and arrays are introduced in 13th chapter).
Is it at all possible?
Well, the program either needs to process each character as you enter it and write out the digit straight away, or it has to store the characters somewhere.
Of course you can make a bunch of variables and use a clumsy kind of nested if to read some characters and store them, but that would be just silly.
Has the book covered strings in some way or another?
Of course you can make a bunch of variables and use a clumsy kind of nested if to read some characters and store them, but that would be just silly.
Code:
int a, b, c, d, e;
a = 0;
b = 0;
c = 0;
d = 0;
e = 0;
if ((a = getchar()) != '\n') {
if ((b = getchar()) != '\n') {
if ((c = getchar()) != '\n') {
if ((d = getchar()) != '\n') {
e = getchar()) != '\n');
}
}
}
}
// and then write them out in a similar nested ifHas the book covered strings in some way or another?
As a former student/teacher of computer science related subjects, i bet whoever corrects this would love a nice recursive function... it just goes off to show you know what you are doing and its far more modular than a simple iteration in the main.
Just a tip, always use functions. If the assignment has any follow-ups, it will make things way easier and faster most of the time. Simple C code will suffice, no need to implement any classes.
I won't elaborate on the function to do this, as I believe the only way of learning is to try by yourself. It's better to get a C and learn something than to copy to get an A.
Just a tip, always use functions. If the assignment has any follow-ups, it will make things way easier and faster most of the time. Simple C code will suffice, no need to implement any classes.
I won't elaborate on the function to do this, as I believe the only way of learning is to try by yourself. It's better to get a C and learn something than to copy to get an A.
This reminds me of a problem I had on a final exam in a programming class. "Write a program that reads a decimal amount in dollars and cents, between 0.01 and 999.99, and prints the English equivalent, e.g., 24.13 would produce "twenty four dollars and thirteen cents". We were to write the program on paper, not on a computer, during the test.
I think I constructed an algorithm to do it, and I got an A on the test. But a classmate told me later that he wrote something like this:
I think I constructed an algorithm to do it, and I got an A on the test. But a classmate told me later that he wrote something like this:
if ( amount == 0.01 ) printf("one cent") ;
else if ( amount == 0.02 ) printf("two cents") ;
...
else if ( amount == 999.99 ) printf("nine hundred ninety nine dollars and ninety nine cents") ;
I guess he assumed either the compiler knew how to fill in the "..." part, or else the professor would understand that his solution was a 99,999-line nested if statement. Either way, I doubt he got a good grade on that problem!else if ( amount == 0.02 ) printf("two cents") ;
...
else if ( amount == 999.99 ) printf("nine hundred ninety nine dollars and ninety nine cents") ;