CONSTANTS

1
CONSTANTS

• Integer Constants
• 1, 4, -98
• Real Constants
• 12.8, -98.9
• Logical Constants
• Character Constants
• 1234, abcd, a, a1s2

2
Variables

• Rules
• Start with a.z, A.Z
• Lengthlt6
• Should not contain special characters
• May have 0..9
• No blanks

3
Variables (Contd)

• Integer Variables
• Explicit
• Integer x, y, z
• Implicit
• Starts with I,J,K,L,M,N
• Real Variables
• Explicit
• Real a, b, c
• Implicit
• Anything other than integer

4
Variables (Contd..)

• Logical Variables
• Character Variables (Explicit only)
• Character varlength
• Character x20, y10
• Character length var
• Character 20 a, b, c

5
Arithmetic Operations

• ? Exponentiation? PREC 1
• ? Multiplication? PREC 2
• / ? Division? PREC 2
• ? Addition? PREC 3
• - ? Subtraction? PREC 3
• Parentheses have the highest priority

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Arithmetic Operations (Contd..)

• Integer Operation
• Result is Integer
• Fraction is truncated
• Real Operation
• Result is real
• Mixed Mode Operation
• Result is real

7
INPUT STATEMENTS

• Read, var1,var2,..
• Data values are separated by commas or blank
• Must match the type in sequence
• Integer x, y
• Real a, b
• Read, x, a, y, b
• Input 10 5.2 3 -9.8
• Wrong Input 5.2 10 1.2 5.6

8
OUTPUT STATEMENTS

• Print, var1, test messsage, var2, 10
• INPUT Keyboard?Memory
• OUTPUT Memory?Monitor

9
EXERCISES

• Type and Execute the program on page 25
• Write a program to calculate the area of a circle
• Write a program to input an integer as days which
  will be converted to years, months and days.