Programming style is a term that describes the way a programmer writes code in a certain programming language.

Programming style is often dependent on the actual choice of programming language one is writing in. C style will vary from BASIC style, and so on.

Table of contents
1 Characteristics of style

Characteristics of style

Good style, being a subjective matter, is difficult to concretely categorize, however there are a number of general characteristics.

Appropriate variable names

Appropriate choices for variable names is seen as the keystone for good style. Code that uses poor names means that the overall functionality of the program is less easy to elucidate.

For example, consider the following pseudocode snippet

get a b c 
if a < 12 and b < 60 and c < 60
  return true
else
  return false
What does this code do? Because of the choice of variable names, this is difficult to work out. However, if we change variable names:

get hours minutes seconds 
if hours < 12 and minutes < 60 and seconds < 60
  return true
else
  return false
we could probably guess correctly it returns true if the time entered is in the AM.

See also: identifier naming convention

Indent style

Indent style, in programming languages that use braces or indenting to delimit logical blocks of code is also a key to good style. Using a logical and consistent indent style makes one's code more readable. Compare

if(hours<12 && minutes<60 && seconds<60)
{
   return true;
}
else
{
   return false;
}
with something like 
if(hours<12 && minutes<60 && seconds<60){return true;}
else{return false;}
The first example is much easier to read in that it is spaced out and logical blocks of code are grouped and displayed together much more clearer.

Looping and control structures

The use of logical control structures for looping adds to good programming style as well. It helps someone reading code to understand the program's sequence of execution (in imperative programming languages). For example, in pseudocode: 
 count = 0
 while count < 5
   print count*2
   count = count + 1
 endwhile
obeys the above two style guidelines, but however the following using the "for" construct makes the code much easier to read. 
 for count = 0, count < 5, count=count+1
   print count*2

Spacing

Certain programming languages ignore whitespace absolutely. Making good use of spacing in one's layout is good programming style.

Compare the following examples of C code. 

 int count;for(count=0;count<10;count++){printf("%d",count*count+count);}
with 
 int count;
 for(count = 0; count < 10; count++)
 {
    printf("%d", count*count + count);
 }