Module 5

JavaScript Operators

CS346 Javascript-5 2

Examples

JS-5 Examples

CS346 Javascript-5 3

Expressions

Expression — combination of literal values, variables, and operators that can be evaluated by JavaScript to produce a result

Operands — variables and literals contained in an expression

Operators — symbols used in expressions to manipulate operands

Performs some sort of calculation, comparison, or assignment on one or more values

CS346 Javascript-5 4

Operators

Arithmetic: + - * / % (int remainder)

Increment: ++++var — Value Incremented Immediately

var count = 1;var newCount = ++count; // newCount = 2

var++ — Value Incremented After Linevar count = 1;var newCount = count ++; // newCount = 1

Decrement: - - Similar to increment

CS346 Javascript-5 5

Operators

Assignment: = += -= *= /= %=var x=1, y=2;x += y; // x = 3

Comparison: == != > < >= <= Results in True or False

var x=1, y=2;x == y; // returns False

Logical: && || ! Results in True or False

var x=1, y=2;var returnVal = x==1 || y==5; // returns True

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Operators

Negation: - Bitwise: logical operators that work at

the bit level (ones and zeros) AND & XOR ^ OR | NOT - Left Shift << Right Shift >> Right Shift (Zero Fill) >>>

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Operators

String + Concatenate

var x=“You age is”, y=18;

var newStr = x + y;

document.write(newStr); // returns Your age is18

document.write(x + “ ” + y + “.”); // returns Your age is 18.

Conditional: boolean? exprT:exprFdocument.write(“The fee is ”+ (isMem ? “$5” :

“$10”));

Beware

Variable type is dynamic Examples

5-1AssignmentExamples.htm Combination of CSS and Javascript Generation of well-formed html document

5-2ComparisonExamples.htm 5-3LogicalExamples.htm