Here’s a question I got today:

I’m trying to prompt the user to enter an array of strings. How do I do that?

Considering I haven’t written a complete C/C++ application in over 5 years I admit I had to dust off the Google a bit, but luckily most of it came back to me. To do this (using C, not C++) we’ll need a pointer array, each item eventually containing a string. This means we’ll have to use malloc() to allocate the memory to hold this information. We then can use an old fashioned loop and scanf() to ask for the user input, and stuff the result into our new array. For good measure we then loop again and display what the user entered. Here’s the code.

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

int main() {
	char** names[4];
	int i = 0;

	printf("Type in 4 names.");

	for (i = 0; i < 4; i++) {
		/*
		 * Use malloc for C apps. For C++,
		 * names[i] = new char*[128];
		 */
		names[i] = (char**) malloc(128);
		scanf("%s", (char*) names[i]);
	}

	printf("Now showing what you typed...");
	for (i = 0; i < 4; i++) {
		printf("%s", names[i]);
	}

	return 0;
}

I admit it was a little fun dusting off that old knowledge, but it also reminds me why I love languages like ColdFusion and Groovy so much. A lot of that memory management nonsense is handled for you, which does make my life easier!