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int main( const int argc , const char[] const argv) As Effective C++ Item#3 states "Use const whenever possible", I start thinking "why not make these 'constant' parameters const "?. Is there any scenario in which the value of argc is modified in a program? In this case, history is a factor. C defined these inputs as "not constant", and compatibility with (a good portion of) existing C code was an early goal of C++. Some UNIX APIs, such as getopt , actually do manipulate argv[] , so it can't be made const for that reason also. (Aside: Interestingly, although getopt 's prototype suggests it won

I am new to Ruby. I'm looking to import functions from a module that contains a tool I want to continue using separately. In Python I would simply do this: def a(): ... def b(): ... if __name__ == '__main__': a() b() This allows me to run the program or import it as a module to use a() and/or b() separately. What's the equivalent paradigm in Ruby? From the Ruby I've seen out in the wild (granted, not a ton), this is not a standard Ruby design pattern. Modules and scripts are supposed to stay separate, so I wouldn't be surprised if there isn't really a good, clean way of doing this. EDIT: Found

What is the difference between char** argv and char* argv[] ? in int main(int argc, char** argv) and int main(int argc, char* argv[]) ? Are they the same? Especially that the first part does not have [] . Fred Foo They are entirely equivalent. char *argv[] must be read as array of pointers to char and an array argument is demoted to a pointer, so pointer to pointer to char , or char ** . This is the same in C . James Bedford They are indeed exactly the same. The golden rule of arrays to remember is: "The name of an array is a pointer to the first element of the array." So if you declare the

I call my swap method in main, but it doesn't change anything. What am I doing wrong? public static void main(String[] args){ int mainArr[] = new int[20]; for(int i = 0; i<mainArr.length; i++){ swapper(3, 14, mainArr); System.out.print(i + mainArr[i] + " "); } } public static void swapper (int a, int b, int[] mainArr){ int t = mainArr[a]; mainArr[a] = mainArr[b]; mainArr[b] = t; } My code yields 0, 1, 2, 3,...19 in normal ascending order, where I want it to swap the 4th and 15th element. Move the method call: - swapper(3, 14, mainArr); outside your for loop. Since, if your loop runs even

I can't compare main() arguments with const char* strings. Simple code for explaining: #include <stdio.h> int main(int argc, char *argv[]) { int i; if(argc>1) { for (i=1;i<argc;++i) { printf("arg[%d] is %s\n",i,argv[i]); if(argv[i]=="hello") printf(" arg[%d]==\"hello\"\n",i); else printf(" arg[%d]!=\"hello\"\n",i); } } return 0; } Simple compile g++ test.cpp . When I try execute it, I see next thing: >./a.out hello my friend arg[1] is hello arg[1]!="hello" arg[2] is my arg[2]!="hello" arg[3] is friend arg[3]!="hello" Whats wrong with my code? In this statement if(argv[i]=="hello") you compare

I am supposed to do the following: Write a Java application (Client) program with a static method called generateEmployees( ) that returns a random list of 10 different types of Employee objects. You could either use an array or an ArrayList to store the employee objects that will be returned. Use a for loop to populate randomly different types of employee objects with some random data. You could possibly think a range of values like 1 – 4. If random value is 1, create a HourlyEmployee object with some randomly generated data, if 2, SalariedEmployee object with some random data and so on. I