Problem with char*

[gReaen]

Hello, This might be a basic point in C++ but i need help...... This is the code snippet i've been using: typedef char* myString; main() { myString i="abcd"; myString j="ABCD"; .... } I need to copy j to i. But i'm not able to use usual strcpy. I also tried assigning char by char using for loop. ( i[1]=j[1] etc). But it didn't work.:confused: I dont want to use array format for the string, it should be char* only. Also i dont want to directly point i to j(i=j) coz it might result in memory leak. Plz, suggest some alternative.....

[Cedric Moonen]

gReaen wrote:

Also i dont want to directly point i to j(i=j) coz it might result in memory leak.

No it won't. Anyway, for such string manipulations, it is much easier to use the string class from the STL (std::string).

Cédric Moonen Software developer
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[CPallini]

A typedef isn't enough to transform a string literal (as well a char pointer) into a string. :)

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler. -- Alfonso the Wise, 13th Century King of Castile.
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[David Crow]

gReaen wrote:

But it didn't work.

The only way that would work would be to change the declarations to:

char i[] = "abcd";
char j[] = "ABCD";

See here for the difference in why one can be changed and not the other.

"Normal is getting dressed in clothes that you buy for work and driving through traffic in a car that you are still paying for, in order to get to the job you need to pay for the clothes and the car and the house you leave vacant all day so you can afford to live in it." - Ellen Goodman

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[Bram van Kampen]

You should never loose sight of the code generated by the compiler. In your case the Compiler will include two char arrays into the excecutable, namely "abcd" and "ABCB" The fact that you Tyedefed them as myString has confused you more than the compiler. You cannot copy i to j, because both are in memory reserved for string constants. In other words: Both are in 'read only' memory. I strongly suggest that you get a copyof the excelent book written by Brian Kernighan and Denis Ritchie about the 'C' language (Never mind CPP). And rephrase the question above after reading these books. If you do the appropriate amount of study,you will realise that in the above example code fragments, memoryleaks are not even close to being an issue.

Bram van Kampen