- The computer has to be told how to process data.
- This task is accomplished through the use of operators in high level languages
- Operators are data connectors within expressions and equations
- The type of operator used in problem solving are mathematical, relational, and logical.
- The operand and the resultant are two concepts related to the operator
- Operands are the data that the operator connects and processes.
- The resultant is the answer that results when the operation is completed. For example 5 + 7
Mathematical Operators:
+, -, /, *, \, MOD, ^
Relational Operators:
<, >, ==, !=, <=, >=
- Operands of relational operators can either be numeric or character, however, they must be of the same type.
- The resultant of relational operation is of logical data type (i.e. either True or False).
Logical Operators:
AND, OR, NOT
- Logical operators are used to connect relational expressions and to perform operations on logical data.
Operator Precedence:
- ()
- Function calls
- NOT, Unary –
- ^ (power)
- /, *, \, MOD
- +, –
- <, <=, >, >=
- ==, !=
- AND
- OR
- =
The data the computer uses are of many different types.
Computer must be told about the data type of each variable or constant.
Numeric Data
- Includes all types of numbers. The subtypes of numeric data type are Integer and Real
- Integers are whole numbers
- Real numbers or floating point numbers are whole numbers plus decimal parts
- A real number can be represented in scientific notation such as 2.5E5 or 3.2E-3. No commas are used.
Character Data
- The character data set consists of all single digit numbers, letters and special characters, available to the computer – placed within quotation marks.
- An uppercase letter is considered different from a lowercase letter.
- When more than one character is put together, the computer considers this item as a string.
- Character and string data are compared and arranged in alphabetical order.
- The computer gives each character a number (ASCII Codes). The numbers are compared to see which is larger and are then arranged in ascending order.
- Upper case letters are given a smaller value than a lowercase letter.
Logical Data
- Consists of only two values – true and false.
- They are used in making yes-or-no decisions.
- For example, to check the credit record.
