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Numeric Data Types in C

Numeric data types in C are used to store numbers. They are divided into integer types for whole numbers and floating-point types for real numbers with fractional parts.

Key Topics

1. Integer Types

Integer types are used to store whole numbers, both positive and negative.

Type Keyword Size (bytes) Range
Short Integershort2-32,768 to 32,767
Integerint2 or 4Depends on system
Long Integerlong4-2,147,483,648 to 2,147,483,647
Long Long Integerlong long8-9,223,372,036,854,775,808 to 9,223,372,036,854,775,807

Example: Using Integer Types

short s = 32000;
int i = 100000;
long l = 2000000000;
long long ll = 9000000000000000000;

printf("Short: %d\n", s);
printf("Int: %d\n", i);
printf("Long: %ld\n", l);
printf("Long Long: %lld\n", ll);

Output:

Short: 32000
Int: 100000
Long: 2000000000
Long Long: 9000000000000000000

Code Explanation: Different integer types are used to store numbers of varying sizes. Format specifiers like %d, %ld, and %lld are used for printing.

2. Floating-Point Types

Floating-point types are used to store real numbers with decimal points.

Type Keyword Size (bytes) Precision
Floatfloat46 decimal places
Doubledouble815 decimal places
Long Doublelong double10, 12, or 1619 decimal places

Example: Using Floating-Point Types

float f = 3.14159f;
double d = 2.7182818284;
long double ld = 1.6180339887;

printf("Float: %.5f\n", f);
printf("Double: %.10lf\n", d);
printf("Long Double: %.10Lf\n", ld);

Output:

Float: 3.14159
Double: 2.7182818284
Long Double: 1.6180339887

Code Explanation: Floating-point numbers are declared and printed with specified precision using format specifiers like %.5f, %.10lf, and %.10Lf.

3. Type Modifiers

Type modifiers like signed, unsigned, short, and long alter the size and range of basic data types.

Example: Unsigned Integer

unsigned int u = 4000000000;

printf("Unsigned Int: %u\n", u);

Output:

Unsigned Int: 4000000000

Code Explanation: The unsigned int type allows for larger positive values by excluding negative numbers.

Best Practices

  • Choose the appropriate data type based on the range of values you expect.
  • Use type modifiers to optimize memory usage and performance.
  • Be mindful of integer overflow and underflow.

Don'ts

  • Don't mix signed and unsigned types without proper handling.
  • Don't assume the size of data types; use sizeof() to confirm.
  • Don't neglect floating-point precision errors in calculations.

Key Takeaways

  • Numeric data types are essential for storing and manipulating numbers in C.
  • Understanding the size and range of each type helps prevent errors.
  • Type modifiers allow for customization of data types to fit specific needs.
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