Assign an arrays values to another array

laczfinador · 05-06-2009, 05:54 AM

Hello World!

I have a file stream called "src" and I am reading in lines from that file. The file contains information about sms messages. The very first line tells us, how many messages are stored in the file. Then, every message takes up two lines: the first line containing information about the date of reception and the sender, the second line containing the message itself, with a length of 100 chars at maximum. The file contains 30 messages, thus it is 60+1 lines long. My task is, to tell which message is the shortest, and which one is the longest. I have started with this code:

Code:

...includes...
...var declarations...

char shortest_msg[100];
char longest_msg[100];

...some code...
...even more code...

for(i=0;i<=number_of_msg*2;i++){
		fgets(current_line,100,src);
		if(i==0)
			continue;
		else if(i/2==0){
		}
		else if(i/2==1){
			if(strlen(shortest_msg)>strlen(current_line))
				shortest_msg=current_line;
			else if(strlen(longest_msg)<strlen(current_line))
				shortest_msg=current_line;
		}
	}

I am trying to assign a character array returned by fgets() to another character array. Both of them are of the same length, 100 chars. The compiler keeps telling me, that there is an "invalid lvalue assignment". What am I doing wrong?

**laserlight** · 05-06-2009, 06:19 AM

You cannot assign to arrays, so you should use say, strcpy() instead.

ReeV · 05-06-2009, 06:23 AM

use memcpy() to copying current_line to shortest_msg, I think you unable to assign another address of pointer ( shortest_msg is address of shortest_msg[0] same as &shortest_msg[0]).

laczfinador · 05-06-2009, 07:46 AM

Greetings, and thanks fro the replies!

The strcpy() function did the job well, and it seems easy to use even. Wish everything couls be solved so easily...

05-06-2009, 05:54 AM	#1
laczfinador Registered User Join Date: Dec 2008 Posts: 13	[SOLVED] Assign an arrays values to another array Hello World! I have a file stream called "src" and I am reading in lines from that file. The file contains information about sms messages. The very first line tells us, how many messages are stored in the file. Then, every message takes up two lines: the first line containing information about the date of reception and the sender, the second line containing the message itself, with a length of 100 chars at maximum. The file contains 30 messages, thus it is 60+1 lines long. My task is, to tell which message is the shortest, and which one is the longest. I have started with this code: Code: ...includes... ...var declarations... char shortest_msg[100]; char longest_msg[100]; ...some code... ...even more code... for(i=0;i<=number_of_msg2;i++){ fgets(current_line,100,src); if(i==0) continue; else if(i/2==0){ } else if(i/2==1){ if(strlen(shortest_msg)>strlen(current_line)) shortest_msg=current_line; else if(strlen(longest_msg)<strlen(current_line)) shortest_msg=current_line; } } I am trying to assign a character array returned by fgets() to another character array. Both of them are of the same length, 100 chars. The compiler keeps telling me, that there is an "invalid lvalue assignment". What am I doing wrong? Last edited by laczfinador; 05-06-2009 at 07:46 AM.*
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05-06-2009, 06:19 AM	#2
laserlight C++ Witch Join Date: Oct 2003 Location: Singapore Posts: 10,352	You cannot assign to arrays, so you should use say, strcpy() instead. __________________ C + C++ Compiler: MinGW port of GCC Build + Version Control System: SCons + Bazaar Look up a C/C++ Reference and learn How To Ask Questions The Smart Way
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05-06-2009, 06:23 AM	#3
ReeV Registered User Join Date: May 2009 Posts: 4	use memcpy() to copying current_line to shortest_msg, I think you unable to assign another address of pointer ( shortest_msg is address of shortest_msg[0] same as &shortest_msg[0]).
ReeV is offline

05-06-2009, 07:46 AM	#4
laczfinador Registered User Join Date: Dec 2008 Posts: 13	Greetings, and thanks fro the replies! The strcpy() function did the job well, and it seems easy to use even. Wish everything couls be solved so easily...
laczfinador is offline

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