Basic concept of js
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The document discusses key concepts in JavaScript including variables, operators, and embedding JavaScript in web pages. It defines variables as containers that store data values and can be declared with keywords like 'var' and 'let'. It also describes different types of operators such as arithmetic, assignment, logical, and comparison operators that are used to perform operations. Finally, it explains that JavaScript code can be embedded in HTML pages inside <script> tags and attributes like language and type are used to specify the scripting language.
Basic concept of js
- 1. • The Sentences is a programming language is called Statement. • The principle, how statement constructed in a programming language is called language Syntax. • Placed with in the “<script>” tags. • Ex : <script>JavaScript statements</script> • <script> have two important attribute • language attribute. • Type attribute. • <script language=“en” type=“text/javascript”>JavaScript statements</script>
- 2. • Javascript can be embedded in the Web page in a following ways : • Inside head Tag<head></head> • Inside body Tag<body></body> • In an External Source File. • Ex : add external JS file to web page: • <script language=“en” type=“text/javascript” src=“external.js”></script>
- 3. • JS Variable are containers for storing data value. • Data can be placed into container and referred by variable name. • Declaration of variable is done by using key “var” or “let” . • Variable can be initialized at declaration or after declaration .
- 4. • Local Variable. • Global Variable • Variable naming convention can not be use reserved keywords. • Case-Sensitive. • Variable name must be begin with a “letter” or “_” or “$”.
- 6. • An operator is explained below: • 3 + 4 = 7 {where ‘+’ is an operator. . And ‘3 & 4’ is an operand. } • Operators are supported : • Arithmatic • Assignment • Shift >> or << • Unary ! • Conditonal • Logical • Bitwise • Comparision • String
- 7. • Arithmatic Operator : • Arithmatic operator is used to arithmatic operation between two or more values or variable. Arithmatic operator are : • ‘+’ operator. • ‘-’ operator. • ‘x’ operator. • ‘/’ operator. • ‘%’ operator. • ‘++’ Increment operator. • ‘- -’ Decrement operator
- 8. • Assignment Operator : • Assignment operator is used to assign values to JavaScript variable. Assignment operator are : • ‘==’ operator. • ‘+=’ operator. • ‘-=’ operator. • ‘*=’ operator. • ‘%=’ operator. • ‘/=’ operator.
- 9. • Logical Operator : • Logical operator is used to determine the logic between JavaScript variable. Logical operator are : • ‘&&’ “AND” operator. • ‘||’ “OR” operator. • ‘!’ “NoT” operator.
- 10. • Comparision Operator : • comparision operator is used to compare two values or variables. Comparision operator are : • ‘==’ operator. • ‘===’ operator. • ‘!=’ operator. • ‘!==’ operator. • ‘>=’ operator. • ‘<=’ operator. • ‘<’ or ‘>’ operator
- 11. • Bitwise Operator : • Bitwise operator works on 32 bit number. • Any numeric operand in the operation converted into 32 bit number. Bitwise operator are : • ‘&’ operator. • ‘|’ operator. • ‘~’ ‘NOT’ operator. • ‘^’ ‘XOR’ operator. • ‘>>’ operator. • ‘<<’ operator. • >>> operator
- 12. • Unary Operator : • Unary operator is used to convert variable to number. • Bitwise operator are :