Punit

he ANSI C standard provides a predefined symbol named __STDC__ that is set to 1 when the compiler is enforcing strict ANSI standard conformance. If you want your programs to be 100 percent ANSI conformant, you should ensure that the __STDC__ symbol is defined. If the program is being compiled with non-ANSI options, the __STDC__ symbol is undefined. The following code segment shows how this symbol can be checked: #ifdef __STDC__ printf("Congratulations! You are conforming perfectly to the ANSI standards!\n"); #else printf("Shame on you, you nonconformist anti-ANSI rabble-rousing programmer!\n"); #endif

The following are the differences: - String can hold only char data. Where as an array can hold any data type. - An array size can not be changed. Where as a string size can be changed if it is a char pointer - The last element of an array is an element of the specific type. The last character of a string is a null – ‘\0’ character. - The length of an array is to specified in [] at the time of declaration (except char[]). The length of the string is the number of characters + one (null character).

The ‘#pragma’ directive is the method specified by the C standard for providing additional information to the compiler, beyond what is conveyed in the language itself. Three forms of this directive (commonly known as pragmas) are specified by the 1999 C standard. A C compiler is free to attach any meaning it likes to other pragmas.

The C preprocessor informs the C compiler of the location in your source code where each token came from. Presently, this is just the file name and line number. All the tokens resulting from macro expansion are reported as having appeared on the line of the source file where the outermost macro was used. We intend to be more accurate in the future. If you write a program which generates source code, such as the bison parser generator, you may want to adjust the preprocessor's notion of the current file name and line number by hand. Parts of the output from bison are generated from scratch, other parts come from a standard parser file. The rest are copied verbatim from bison's input. You would like compiler error messages and symbolic debuggers to be able to refer to bison's input file.