How to parse a string that's in one index of an array?

Question

I'm writing a program in C that receives two strings as input from the user on the command line. I know that when you use

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

it creates a pointer to the array that stores both arguments as argv[1] and argv[2]. Say the user inputs "hello" on the command line, and I want to access the individual characters in "hello", how can I do so if argv[1] gives me the whole string rather than individual characters?

argv[x] (for any valid x) is a string. You access individual elements of that like you do for any other string. You have encountered array of arrays before? Treat argv like an array of arrays. — Some programmer dude
– Some programmer dude, Commented Feb 14, 2019 at 5:30
@SaniJr: argv here is a 2 dimensional array. so in your example argv[1][0] is 'h', argv[1][1] is 'e' and so on. so you can run a for loop to the length of argv[1] and get each entry with argv[1][i]. — Deepak
– Deepak, Commented Feb 14, 2019 at 5:32
@Deepak Thanks a lot that's what I was looking for. Didn't think of it as a 2D array. — Sami
– Sami, Commented Feb 14, 2019 at 5:41
argv is not a 2D array. argv is a pointer, a pointer to a char *. — chux
– chux, Commented Feb 14, 2019 at 6:05
Sorry, it is not a 2D array. It is a pointer to a pointer. where each row can string can have its own size of character. it will not have the fixed dimension. — Deepak
– Deepak, Commented Feb 14, 2019 at 6:39

Sourav Ghosh · Accepted Answer · 2019-02-14 05:39:08Z

1

TL;DR- When in doubt, check the data type.

The type for argv is char * [], which decays to char **. Thus, argv[n] is of type char *.

You can index into argv[n], like argv[n][m] to get the char elements.

edited Feb 14, 2019 at 5:39

answered Feb 14, 2019 at 5:30

Sourav Ghosh

135k17 gold badges192 silver badges271 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

lwzhuo · Accepted Answer · 2019-02-14 05:49:15Z

0

You can treat char *argv[] to a string array.

As the char * is a pointer which point to char array(also can treat as a string).

So the argv[0],argv[1].... are the char* data type, the argv[0][0] is char data type.

answered Feb 14, 2019 at 5:49

lwzhuo

3242 silver badges6 bronze badges

Collectives™ on Stack Overflow

How to parse a string that's in one index of an array?

2 Answers 2

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related