CODEWITHSUNDEEP
c++
Narf the Mouse
Narf the Mouse

Reputation: 1568

Attempting to write a String constructor to handle static char * such as "Hello World"

I've got a String class. Recently, I found the poor thing couldn't handle: 

String string = "Hello World";

I immediately decided to rectify this by adding a constructor. However, the exact parameter eludes me: 

inline String(const char[] str) : Array(str, sizeof(str) / sizeof(char)) { }

generates the following error: "error C2146: syntax error : missing ')' before identifier 'str'"

What I'm thinking is that since it's a static char * literal, it isn't meant to be passed to a function. But, I don't actually know.

Thanks. (To reassure - Any array passed to Array will promptly be copied, not stored)

Upvotes: 1

Views: 162

Answers (3)

Ken Wayne VanderLinde
Ken Wayne VanderLinde

Reputation: 19347

This particular error is generated because the square brackets [] should go after str, not after char. Change this and the error should disappear.

However, I don't think your calculation sizeof(str) / sizeof(char) will work, because when an array is used as a parameter, you lose the information regarding the length of the string. It only work if you are using the original array. The calculation you perform will be equivalent to sizeof(char *) / sizeof(char), which will not reflect the size of the string. Instead, do as Asha says and use strlen and strcpy.

Upvotes: 0

Eugene Burtsev
Eugene Burtsev

Reputation: 1475

You not need to use sizeof(char) - according to standard of C++ sizeof(char) always equals 1.

Upvotes: 0

Asha
Asha

Reputation: 11232

Simplest would be to take const char* as the parameter. Then use strlen to find the string length, then allocate len+1 characters using new and use strncpy to copy the string to the newly allocated memory. BTW, any specific reason not to use std::string?

Upvotes: 4

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