Control structures are features of programming languages that influence the code flow. Two common examples are loops and conditions. The task here is to demonstrate control structures supported by different programming languages.

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Iterative

These control structure operate on datasets.

C++

for_each

Compiler: GCC 4.1.1

 #include <iostream>  // std::cout, std::endl
 #include <vector>    // std::vector
 #include <algorithm> // std::for_each
 
 struct sum
 {
   int _sum;                                    
   sum() : _sum(0) {};                         // Initialize sum with 0;
   void operator() (int a) { _sum += a; }      // this function will be called for every element
 };
 
 int main()
 {
   std::vector<int> v;
   v.push_back(10);
   v.push_back(23);
   v.push_back(34);
 
   /* Note that for_each gets a fresh instance of sum passed,
    * applies every element beginning with *v.begin() up to,
    * but not including v.end() to the function object
    * and returns a copy of it.
    */
 
   sum the_sum = std::for_each(v.begin(), v.end(), sum());
 
   std::cout << "The sum is " << the_sum._sum << std::endl;
   return 0;
 }

Tcl

foreach

foreach i {foo bar baz} {
    puts "$i"
}

UNIX Shell

for

Interpreter: Bourne Again SHell

#!/bin/bash
ARRAY="VALUE1 VALUE2 VALUE3 VALUE4 VALUE5"

for ELEMENT in $ARRAY
do
 echo $ELEMENT # Print $ELEMENT
done

Interpreter: Debian Almquist SHell

#!/bin/sh
ARRAY="VALUE1 VALUE2 VALUE3 VALUE4 VALUE5"

for ELEMENT in $ARRAY
do
 echo $ELEMENT # Print $ELEMENT
done