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The Need for a Compound Statement

6 February, 2015 - 15:00

For illustration we will use the syntax for the if then else control structure within the C++ programming language. However this problem generally exists for all control structures within any language that requires the use of compound statements. The syntax is:

if (expression)   statement; else   statement; 

Within the C++ programming language there can be only one statement listed as the action part of a control structure. Often, we will want to do more than one statement. This problem is overcome by creating a compound statement. The brace symbols the opening { and the closing } -are used to create a compound statement. For example:

if(expression)   {   statement;   statement;   } else   {   statement;   statement;   } 

Because programmers often forget that they can have only one statement listed as the action part of a control structure; the C++ programming industry encourages the use of indentation (to see the action parts clearly) and the use of compound statements (braces), even if there is only one action. Thus:

if(expression)  {  statement;  }else  {  statement;  }

By writing code in this manner, if the programmer modifes the code by adding more statements to either the action true or the action false; they will not introduce either compiler or logic errors. Using indentation and braces should become standard practice for C++ programmers and programmers in any other language that require the use of compound statements with the control structures.