The Psychology of Quality and More

C Style: Standards and Guidelines (contents)

CHAPTER 9 : Data Usage

PART 4 : USAGE

CHAPTER 9 : Data Usage
9.1 Declarations
9.2 Using floating point numbers
9.3 Using 'typedef'
9.4 Using global data
9.5 Using Structures
9.6 Using Unions
9.7 Using Arrays
9.8 Using Pointers
9.9 Using bit structures
9.10 Using Constants
9.11 Using 'static' declarations
9.12 Initializing variables
9.13 Summary

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9.2  Using floating point numbers

Floating point variables should be explicitly kept for floating point numbers. They should never be used where an integer will suffice, as 1.0 does not necessarily equal 1. By the same token, using floating point numbers for loop variables should be avoided, as should any tests for exact value (use >= and <=):

if ( Pi != 3.14159)
    printf( "Has Pi been corrupted?\n");

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float and double are analogous to short and int, in that floats are usually converted to doubles in expressions. Thus if you require limited accuracy or need to save space (eg. in arrays), then use float. Otherwise, and especially if you are unsure of the required accuracy, use double.

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