Lecture on Data Types in C

Overview

This lecture discusses various data types in C programming, expanding upon topics previously covered, focusing on how they store data and how to display them using format specifiers.

Characters (Chars)

• Single Character:
  • Stores one character.
  • Display using %c format specifier.
• Array of Characters:
  • Stores strings or multiple characters.
  • Display using %s format specifier.

Floating Points

• Float:
  • Stores decimal numbers.
  • Uses 4 bytes, 32 bits of precision.
  • Significant digits: 6-7.
  • Display using %f format specifier.
• Double:
  • Double precision of a float.
  • Uses 8 bytes, 64 bits of precision.
  • Significant digits: 15-16.
  • Display using %lf or %.15lf for more precision.
  • More accurate than float but uses more memory.

Booleans

• In C:
  • Include stdbool.h.
  • Stores true (1) or false (0).
  • Display using %d format specifier.

Chars as Integers

• Range:
  • Stores integers between -128 to 127.
  • Display using %d for decimals or %c for characters using ASCII table.
• Unsigned Char:
  • Range: 0 to 255.
  • Display using %d.
  • Overflow resets to 0.

Short Integers

• Short Int:
  • Uses 2 bytes.
  • Range: -32,768 to 32,767.
  • Display using %d.
• Unsigned Short Int:
  • Range: 0 to 65,535.
  • Overflow resets to minimum value.

Standard Integers

• Integer:
  • Uses 4 bytes.
  • Range: ~-2 billion to 2 billion.
  • Display using %d.
• Unsigned Integer:
  • Range: 0 to ~4 billion.
  • Display using %u.
  • Overflow causes reset.

Long Long Integers

• Long Long Int:
  • Uses 8 bytes.
  • Range: ~-9 quintillion to 9 quintillion.
  • Display using %lld for signed, %llu for unsigned.
• Unsigned Long Long Int:
  • Range: 0 to ~18 quintillion.
  • Warning for large constants can be avoided by appending u.

Key Points

• Chars can store single characters or integers within a specified range.
• Floats and doubles are used for decimal numbers; doubles offer more precision.
• Booleans represent binary states.
• Short/long integers extend or narrow the range of standard integers.

Focus

• Primary focus on chars, arrays of chars, doubles, booleans, and integers.
• Be aware of other types for specific use cases.