09. session 9 operators and statements
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This document describes different types of operators and statements in JavaScript. It explains arithmetic, relational, logical, assignment, bitwise, and special operators. It also covers increment and decrement operators, arithmetic operators, relational operators, logical operators, assignment operators, bitwise operators, string operators, shift operators, and regular expressions. The document discusses if, if-else, if-else if else, switch-case statements and nested if statements for decision making. It provides examples of operators and statements.
09. session 9 operators and statements
- 1. Operators and Statements Session 9
- 2. Objectives Describe assignment operators Explain bitwise operators Explain switch-case statement Describe regular expression
- 3. Types of Operators Operators help in simplifying expressions. JavaScript provides a predefined set of operators that allow you to perform different operations. Arithmetic operators Relational operators Logical operators Assignment operators Bitwise operators Special operators
- 4. Arithmetic Operator Arithmetic operators are binary operators, as they perform basic arithmetic operator on two operand.
- 5. Increment and decrement operators The increment operator (++) increases the value by 1, while the decrement operator(--) decreases the value by 1.
- 6. Relational Operators Relational operators are binary operators that make compare between two operands. They return a boolean value namely, true or false.
- 7. Logical Operators Logical operators are binary operators that perform logical operations on two operands.
- 8. Assignment Operators Assignmentoperator performs operations between the two operands and assign the result to its left operand.
- 9. Bitwise Operators Bitwise operators perform operations on the corresponding individual bits of two operands.
- 10. Special Operators •There are some operators in Javascript, which do not belong to any of the categories of JavaScript operators
- 11. String Operators Can merge two string values that are assigned to two different variables. Operator Descriptin Example + Concatenates two or var fullname=‘John’ + ‘ ’ + more strings into a ‘Blake’; single string fullname=‘John Blake’ += Concatenates to or var flower=‘Rose’; (Add-By-Value) more strings and flower +=‘’ + ‘flower’; assign the result to its flower =‘Rose Flower’; left operant
- 12. Shift Operators Shift operators are binary bitwise operators that perform shift operations on bits. The first operand is the decimal number on which the shift operation is performed. The second operand specifies the number or bit positions by which the bits are to be shifted. Operator Description Example << Shift the bit positions 8<<2 yield 32,because 00001000 (Left Shift towards the left by shifting shifted by 2 bits becomes Operator) the number of bits in the 00100000,which is 32. Here, the left at the right two leftmost bits are placed toward the right >> Shift the bit positions 8>>2 yield 32,because 00001000 (Right Shift towards the right by shifting shifted by 2 bits becomes Operator) the number of bits in the 00000010,which is 2. Here, the right at the left two rightmost bits are placed toward the left.
- 13. Decision – making Statement Decision-making statement s allow implementing logical decision for executing different block to obtain the desired output. They execute a block of statements depending upon a boolean condition. This condition is an expression that returns either true or false. Javascript supports four decision-making statements : If If-else If-else if else switch
- 14. The “if” Statement The if statement executes a block of statements based on a logical boolean condition.
- 15. The “if-else” Statement The if statement specifies a block of statement to be executed when the condition in the if statement is true, and it’s requires to define a block of statements to be executed when a conditions evaluated to false
- 16. The “if-else if ” Statement The if-else if statements allow you to check multiple conditions and specify a different block to be execute for each condition.
- 17. Nested “if” Statement The nested if statements comprises of multiple if statements within an if statement.
- 18. “Switch-case” Statement To simplify the coding and avoid using multiple if statement, switch-case statement can be used as a different approach to code the same logic
- 19. Regular Expressions A regular expression is a pattern, whose purpose is to help in validating the text format Example:
- 20. Types Character or symbols allow matching a substring that exists at a specific position within a string.
- 21. Types Characters or symbols are combined to form character classes for specifying patterns.
- 22. Summary The & operator perform bitwise AND operation and returns the result to the operand on the left hand side The | operator performs bitwise OR operation and returns the result to the operand on the left hand side The ^ operator performs bitwise XOR operation and returns the result to the operand on the left hand side The string concatenation operator combine different strings into single string.
- 23. Summary… The left shift operator shifts the bits on the leftmost side toward the right. The right shift operator shifts the bits on the rightmost side toward the left. Nested switch-case construct refers to including a switch-case construct within a case block. Building Dynamic Websites/Session 1/ 23 of 16