Yahoo Web Search

Search results

1. Top results related to what are the function of dictionary in c compiler and interpreter code

   • What are the differences between using pure C with a C compiler and the "C part" of a C++ compiler?

     Top Answer

     Answered Sep 06, 2010 · 34 votes

     There are a lot of minor nitpicks. One that strikes me as being the most obvious is that in C++, you have to cast the return value of malloc. Also structs are automatically typedefed in C++.

     Always use a C compiler for C code, not C++. C++ isn't perfectly compatible with C.

     A few others:

     • In C, declaring void func(); declares a function that hasn't specifed what its arguments are, whereas in C++, void func(); is equivalent to the C void func(void)', taking no arguments;
     • Prototypes are required in C++, whereas it's generally just a warning in C;
     • The type of character constants (like 'a') is int in C and char in C++;
     • The type of string literals is char [] in C and const char [] in C++;
     • Some legitimate variable names in C, like class, are reserved keywords in C++.

     For all those who don't believe me and are downvoting, check out this C code:

     #include <stdlib.h>-int main(int argc, char **argv) { int *i = malloc(sizeof(int));- return 0;}-

     Compilation under gcc is fine, but compilation under g++ gives the following errors:

     test.c: In function `int main(int, char**)':test.c:4: error: invalid conversion from `void*' to `int*'-

     Check all answers on Stack Overflow

     1/5

   • What are the pros and cons of using extern variables in C in production code?

     Top Answer

     Answered Jul 11, 2019 · 6 votes

     One can share a variable between files in (at least) four ways. You already mentioned two of them:

     • using extern: it will be a global variable, anyone will be able to modify it, not thread-safe; the use of global variables should be minimized;
     • passing a pointer to the the variable: it will provide read / write access to the variable;
     • passing the value of the variable: provides read-only access to the variable;
     • using an access function.

     The function can be as simple as:

     float read_speed(){ return speed;}-

     If the variable needs to be modified also, another function can be provided:

     void write_speed(float new_speed){ speed = new_speed;}-

     The advantage of using access functions is that it separates the variable from the other files. If needed, you can provide several functions for the same variable, for different needs.

     The cost is that code will increase a little and speed will decrease lightly.

     Compare:

     float read_speed_mph(); // get speed in miles per hourfloat read_speed_mps(); // get speed in meters per second-

     They both return the same speed, expressed in different units. The body of the functions will make the right calculation to provide the correct value, while the variable will remain unmodified.

     Check all answers on Stack Overflow

     2/5

   • What are the Roles of Java Compiler and Interpreter?

     Compiler and Interpreter are two different ways to translate a program from programming or scripting language to machine language. In this article let’s discuss on what are the roles of the Compiler and Interpreter in Java.

     Java Compiler

     A compiler in Java translates the entire source code into a machine-code file or any intermediate code, and that file is then executed. It is platform-independent. A bytecode is basically an intermediate code generated by the compiler after the compilation of its source code. Java compiler can be operated by using the “Javac.exe” command from the command prompt. Some of the compiler options are given below:

     • -help: it prints a summary of standard options.
     • -version: returns the compiler information.
     • -verbose: verbose output i.e., it includes information about each source file compiled and each class loaded.
     • -nowarn: it is used to turn off warnings. 

      

     Java Compiler Step By Step

      

     Roles of...

     Check all answers on Geeksforgeeks

     3/5

   • What are the Roles of Java Compiler and Interpreter?

     Compiler and Interpreter are two different ways to translate a program from programming or scripting language to machine language. In this article let’s discuss on what are the roles of the Compiler and Interpreter in Java.

     Java Compiler

     A compiler in Java translates the entire source code into a machine-code file or any intermediate code, and that file is then executed. It is platform-independent. A bytecode is basically an intermediate code generated by the compiler after the compilation of its source code. Java compiler can be operated by using the “Javac.exe” command from the command prompt. Some of the compiler options are given below:

     • -help: it prints a summary of standard options.
     • -version: returns the compiler information.
     • -verbose: verbose output i.e., it includes information about each source file compiled and each class loaded.
     • -nowarn: it is used to turn off warnings. 

      

     Java Compiler Step By Step

      

     Roles of...

     Check all answers on Geeksforgeeks

     4/5

   • What are the different between calling constructor and calling function pointer of constructor in C++

     Top Answer

     Answered Jan 28, 2024 · 0 votes

     Calling a constructor and calling a function pointer of a constructor in C++ are very similar in the sense that they are both quite impossible:

     • You cannot call a constructor in C++.
     • You cannot obtain a pointer to a constructor in C++.

     According to the C++ spec about constructors:

     Constructors have no names and cannot be called directly.

     So, in C++, you do not call constructors. The language does that for you when you use the new keyword, when you declare an object on the stack, etc. The expression new MyClass() might look like a constructor invocation, and it does in fact contain a constructor invocation, and so it might be mistaken for a constructor invocation, but that's not what it is; it is a "new expression", which includes, among other things, an invocation of a constructor. But the other things are crucial: you cannot just skip them and directly invoke the constructor.

     Function pointers of constructors do not exist because normally you cannot take the address of a constructor. If you examine the names exported by the DLL, and somehow figure out which name corresponds to the constructor, and use that name to obtain the entry point of that constructor from the DLL, you are cheating: you are doing something which is not normally supported by the language. As a result, you should not attempt to invoke that entry point. A constructor is only supposed to be invoked by the language.

     Also according to the C++ spec:

     A constructor is a special non-static member function of a class.

     (Emphasis mine.)

     A constructor assumes that memory has been allocated, and proceeds to initialize that memory. The language takes care of the memory allocation, but invoking the constructor directly does not. Since a constructor is non-static, it expects an uninitialized this to be passed to it, but you are not allocating any memory and you are not passing anything to the constructor. The result is exactly as expected: a crash.

     And besides, think about it: the constructor could not be internally allocating the memory, because how would it work then if the object was allocated on the stack? And how would it work if the constructor was being invoked by the constructor of a derived class which presumably occupies more memory?

     You can get your DLL to work by using a factory method. A factory method is a public static method which executes new ClassA() and returns the result, or declares ClassA() and returns it by value. Then, obtain the address of the factory method from the DLL, and invoke it.

     Check all answers on Stack Overflow

     5/5

   Show moreShow less

2. www.geeksforgeeks.org › implementation-on-map-orImplementation on Map or Dictionary Data Structure in C

   www.geeksforgeeks.org › implementation-on-map-or

   • Cached

   Mar 27, 2023 · Last Updated : 27 Mar, 2023. C programming language does not provide any direct implementation of Map or Dictionary Data structure. However, it doesn’t mean we cannot implement one. In C, a simple way to implement a map is to use arrays and store the key-value pairs as elements of the array .

3. stackoverflow.com › questions › 4384359data structures - Quick Way to Implement Dictionary in C ...

   stackoverflow.com › questions › 4384359

   • Cached

   159. Section 6.6 of The C Programming Language presents a simple dictionary (hashtable) data structure. I don't think a useful dictionary implementation could get any simpler than this. For your convenience, I reproduce the code here. struct nlist { /* table entry: */. struct nlist *next; /* next entry in chain */.

   Code sample

   struct nlist {

     struct nlist *next;

     char *name;

     char *defn;

   };...

   See more on stackoverflow

4. People also ask

   Does C# use both compiler and interpreter?

   • It takes the program, one line at a time, and translates each line before running it: It translates the first line and runs it, then translates the second line and runs it etc. Compiler characteristics: Interpreter characteristics: so c# uses both compiler and interpreter? That's not correct. Both languages are both compiled and interpreted.

   How does an interpreter/compiler work - Stack Overflow

   stackoverflow.com/questions/2377273/how-does-an-interpreter-compiler-work

   See all results for this question

   What does a compiler do?

   • Compiler The language processor that reads the complete source program written in high-level language as a whole in one go and translates it into an equivalent program in machine language is called a Compiler. Example: C, C++, C#. In a compiler, the source code is translated to object code successfully if it is free of errors.

   Language Processors: Assembler, Compiler and Interpreter

   www.geeksforgeeks.org/language-processors-assembler-compiler-and-interpreter/

   See all results for this question

   How does a compiler interpret a source code?

   • A compiler bundles the entire source code and translates it once only. So it takes your whole source code as input, which it converts and sends to the CPU to get an output. For interpreted code, errors are more traceable since the interpreter can report them by directly referring to the original source.

   Interpreters and Compilers: What Are They and How Are They Different…

   www.makeuseof.com/interpreters-compilers-what-how-different/

   See all results for this question

   What is the difference between compiler and interpreter?

   • Compiler, transforms source code in one computer language to another one. Interpreter, executes source code directly (usually inside its own virtual machine). (source: answers.com) Generally interpreter is performance costly. Nearly all interpreters execute compiled byte code, and some (simulators) execute compiled machine code.

   How does an interpreter/compiler work - Stack Overflow

   stackoverflow.com/questions/2377273/how-does-an-interpreter-compiler-work

   See all results for this question

5. www.geeksforgeeks.org › language-processorsLanguage Processors: Assembler, Compiler and Interpreter

   www.geeksforgeeks.org › language-processors

   • Cached

   Mar 8, 2024 · Interpreter. A compiler is a program that converts the entire source code of a programming language into executable machine code for a CPU. An interpreter takes a source program and runs it line by line, translating each line as it comes to it. The compiler takes a large amount of time to analyze the entire source code but the overall execution ...

6. www.makeuseof.com › interpreters-compilers-whatInterpreters and Compilers: What Are They and How Are They ...

   www.makeuseof.com › interpreters-compilers-what

   • Cached

   Jul 12, 2023 · Code Execution: Input and Output Processing. An interpreter can only collect, translate, and execute each input per line. It runs each line of the source code sequentially as it comes, and the final output depends on what each line outputs during execution. A compiler bundles the entire source code and translates it once only.

   • Occupation: Staff Writer

7. builtin.com › compiler-vs-interpreterCompiler vs. Interpreter in Programming | Built In

   builtin.com › compiler-vs-interpreter

   • Cached

   Apr 24, 2023 · A compiler translates code written in a high-level programming language into a lower-level language like assembly language, object code and machine code (binary 1 and 0 bits). It converts the code ahead of time before the program runs. An interpreter translates the code line-by-line when the program is running.

8. en.wikipedia.org › wiki › Interpreter_(computing)Interpreter (computing) - Wikipedia

   en.wikipedia.org › wiki › Interpreter_(computing)

   • Cached

   A compiler can thus make almost all the conversions from source code semantics to the machine level once and for all (i.e. until the program has to be changed) while an interpreter has to do some of this conversion work every time a statement or function is executed. However, in an efficient interpreter, much of the translation work (including ...

9. www.freecodecamp.org › news › what-is-a-compiler-in-cWhat is a Compiler? Compilers in C Explained for Beginners

   www.freecodecamp.org › news › what-is-a-compiler-in-c

   • Cached

   Mar 14, 2022 · First step: This code will print “Hello world” The second step is to compile it. It will be compiled according to the compiler you have. gcc -o main main.c -Wall Second step: Command to compile c code. The third and final step is simply getting to know the output of the program – to make sure it is running like we want.