These are called Variadic functions. Wikipedia lists example code for C++. To portably implement variadic functions in the C programming language, the standard stdarg.h header file should be used. The older varargs.h header has been deprecated in favor of stdarg.h. In C++, the header file cstdarg should be used. To create a variadic function, an … Read more
These type of functions are called variadic functions (Wikipedia link). They use ellipses (i.e., three dots) to indicate that there is a variable number of arguments that the function can process. One place you’ve probably used such functions (perhaps without realising) is with the various printf functions, for example (from the ISO standard): int printf(const … Read more
JLS 15.12.2 is the relevant bit of the spec to look at here. In particular – emphasis mine: The remainder of the process is split into three phases, to ensure compatibility with versions of the Java programming language prior to Java SE 5.0. The phases are: The first phase (ยง15.12.2.2) performs overload resolution without permitting … Read more
Yes you can do it in C using what are referred to as Variadic Functions. The standard printf() and scanf() functions do this, for example. Put the ellipsis (three dots) as the last parameter where you want the ‘variable number of parameters to be. To access the parameters include the <stdarg.h> header: #include <stdarg.h> And … Read more
This is a known problem. On some architectures (in particular x86-64), va_list needs to be more complex than a simple pointer to the stack, for example because some arguments might be passed in registers or out-of-band in some other way (see this answer for the definition of va_list on x86-64). On such architectures, it is … Read more
In Java it’s called varargs, and the syntax looks like a regular parameter, but with an ellipsis (“…”) after the type: public void foo(Object… bar) { for (Object baz : bar) { System.out.println(baz.toString()); } } The vararg parameter must always be the last parameter in the method signature, and is accessed as if you received … Read more
Arrays have been around from the beginning of Java, while varargs are a fairly recent addition. Thus a lot of older code still happily uses arrays. Note also that calling a generic vararg method with an explicit array parameter may silently produce different behaviour than expected: public <T> void foo(T… params) { … } int[] … Read more
The numbers: Int… parameter in sumOf is called a variadic parameter. That means you can pass in a variable number of that type of parameter, and everything you pass in is converted to an array of that type for you to use within the function. Because of that, the numbers parameter inside average is an … Read more
Test.class.getDeclaredMethod(“foo”, String[].class); works. The problem is that getMethod(..) only searches the public methods. From the javadoc: Returns a Method object that reflects the specified public member method of the class or interface represented by this Class object. Update: After successfully getting the method, you can invoke it using: m.invoke(this, new Object[] {new String[] {“a”, “s”, … Read more
Write a va_list version of your variadic method; + (NSError *)executeUpdateQuery:(NSString *)query, … { va_list argp; va_start(argp, query); NSError *error = [MyClassName executeUpdateQuery: query args:argp]; va_end(argp); return error; } + (NSError *)executeUpdateQuery:(NSString *)query args:(va_list)args { NSLogv(query,args); return nil; } This can then be called from Swift MyClassName.executeUpdateQuery(“query %d, %d %d”, args: getVaList([1,2,3,4])) Add an extension … Read more