C program to find substring in string - c

Question

So I may be attacking this the wrong way; I was learning a bit of Javascript and wrote a program that will find a string contained in another string and store the matches in an array (sorry if that didn't make too much sense, seeing my C program should help). I tried to translate my program to C, but it doesn't work; I think my issue is data types:
int main () {
char text[58];
strcpy(text, "I am James, James the Great, a pretty cool guy named James");
char store[16];
char name[6] = "James";
for (int i = 0; i <= 16; i++) {
if (text[i] == 'J') {
for (int k = i; k < i + 6; k++) {
store[k] = text[i];
}
}
}
int a = sizeof(store) / sizeof(store[0]);
for (int b = 0; b < a; b++) {
/* This should print out the values stored in the store array */
printf("%d", store[b]);
}
return 0;
}
My expected result would be something like:
JamesJamesJames
Instead I get:
10000747474747474-6374747474
So I'm assuming it's doing exactly what I told it to do, just not storing the letters into the array as letters, a bit confusing. Is there a better way to do this?
This is the javascript code I was trying to translate:
var text = "I am James, James the Great, a pretty cool guy named James";
var myName = "James";
var hits =[];
for (i = 0; i < text.length; i++) {
if (text[i] === "J") {
for (var j = i; j < i + myName.length ; j++) {
hits.push(text[j]);
}
}
}
if (hits.length === 0) {
console.log("Your name wasn't found!");
} else{
console.log(hits);
}

Answer 1

You are going to break store[] with this line
for (int k = i; k < i + 6; k++) {
because you are writing to the same index as you found the text in text[]. You also loop one too many times (6)
int ind = 0;
for (int k = 0; k < 5; k++) {
store[ind++] = text[i+k];
}
Then your next statement doesn't tell you anything about the data you collected
int a = sizeof(store) / sizeof(store[0]);
Just remove it, and print ind characters from store[].

Answer 2

You made following mistakes.
for (int i = 0; i <= 16; i++)
You iterate by '16' but this isn't proper length of text.
for (int k = i; k < i + 6; k++)
So you iterate by "i, i+1, i+2, i+3, i+4, i+5, i+6" here is 7 chars, "James" have 6.
store[k] = text[i];
You aren't changing "i" value so text[i] always return 'J'. It's better to use savePoistion variable so do I in the following code.
int a = sizeof(store) / sizeof(store[0]);
for (int b = 0; b < a; b++) {
/* This should print out the values stored in the store array */
printf("%d", store[b]);
}
I have no idea what are you trying to do here. It's really unnecessary.
printf("%d", store[b]);
"%d" means that you are printing integers so don't be surprised that your output was numbers. Just simply printf("%s\n", store);
This should look like this
int main () {
char text[58];
strcpy(text, "I am James, James the Great, a pretty cool guy named James");
char store[20];
int len = strlen(text);
int savePosition = 0;
int i, k;
for (i = 0; i < len; i++) {
if (text[i] == 'J') {
for ( k = i; k < i + 5; k++) {
store[savePosition] = text[k];
++savePosition;
}
}
}
store[savePosition] = '\0';
printf("%s\n", store);
return 0;
}

Answer 3

int main (void) {
char text[] = "I am James, James the Great, a pretty cool guy named James";
char name[] = "James";
char store[16] = {0};
int store_index = 0;
for (int i = 0; i < strlen(text); i++) {
if (text[i] == 'J') {
for (int k = i; k < i + strlen(name); k++) {
store[store_index++] = text[k];
}
}
}
if(strlen(store)==0) {
printf("Your name wasn't found!\n");
} else {
printf("%s\n", store);
}
return 0;
}
rewrite version.
int main (void) {
char text[] = "I am James, James the Great, a pretty cool guy named James";
char name[] = "James";
char store[sizeof(text)];
char *p = strstr(text, name);
if(p == NULL) {
printf("Your name wasn't found!\n");
} else {
int len = strlen(name);
int index = 0;
do {
memcpy(store + index, name, len);
index += len;
p = strstr(p + len, name);
} while(p != NULL);
store[index] = 0;
printf("%s\n", store);
}
return 0;
}