Kennedybr var date p document writespeaker document

"<p>John F. Kennedy</br>" ;
var date = 'June 26, 1963</p>' ;
document .write(speaker);
document .write(date);

Working with Strings
(cont’ d.)
 String operators
–
Concatenation operator (+): combines two strings
var destination = "Honolulu" ;
var location = "Hawaii" ;
destination = destination + " is in " + location;
 Compound assignment operator (+=): combines
two strings
var destination = "Honolulu" ;
destination += " is in Hawaii" ;
 Plus sign
–
Concatenation operator and addition operator
JavaScript, Sixth Edition 31

Working with Strings
(cont’ d.)
 Escape characters and sequences
–
Escape character
•
Tells the compiler or interpreter that the character that follows
has a special purpose
•
In JavaScript, escape character is backslash (\)
–
Escape sequence
•
Escape character combined with other characters
•
Most escape sequences carry out special functions
JavaScript, Sixth Edition 32

JavaScript, Sixth Edition 33
Table 2-4 JavaScript escape sequences
Working with Strings (cont’d.)

Using Operators to Build
Expressions
JavaScript, Sixth Edition 34
Table 2-5 JavaScript operator types (continues)

JavaScript, Sixth Edition 35
Table 2-5 JavaScript operator types (cont'd.)
Using Operators to Build Expressions
(cont’d.)

Using Operators to Build
Expressions (cont’ d.)
 Binary operator
–
Requires an operand before and after the operator
 Unary operator
–
Requires a single operand either before or after the
operator
JavaScript, Sixth Edition 36

Arithmetic Operators
 Perform mathematical calculations
–
Addition, subtraction, multiplication, division
–
Returns the modulus of a calculation
 Arithmetic binary operators
JavaScript, Sixth Edition 37
Table 2-6 Arithmetic binary operators

Arithmetic Operators
(cont’ d.)
 Arithmetic binary operators (cont’d.)
–
Value of operation on right side of the assignment
operator assigned to variable on the left side
–
Example: arithmeticValue = x + y ;
•
Result assigned to the arithmeticValue variable
–
Division operator (/)
•
Standard mathematical division operation
–
Modulus operator (%)
•
Returns the remainder resulting from the division of two
integers
JavaScript, Sixth Edition 38

JavaScript, Sixth Edition 39
Figure 2-13 Division and modulus expressions
Arithmetic Operators (cont’d.)
var divisionResult = 15 / 6 ;
var modulusResult = 15 % 6 ;
document .write( "<p>15 divided by 6 is " ↵
+ divisionResult + ".</p>" ); // prints '2.5'
document .write( "<p>The whole number 6 goes into 15 twice, ↵
with a remainder of " + modulusResult + ".</p>" );↵ // prints '3'

Arithmetic Operators
(cont’ d.)
 Arithmetic binary operators (cont’d.)
–
Assignment statement
•
Can include combination of variables and literal values on
the right side
•
Cannot include a literal value as the left operand
–
JavaScript interpreter
•
Attempts to convert the string values to numbers
•
Does not convert strings to numbers when using the addition
operator
JavaScript, Sixth Edition 40

Arithmetic Operators
(cont’ d.)
 Prefix operator
–
Placed before a variable
 Postfix operator
–
Placed after a variable
JavaScript, Sixth Edition 41
Table 2-7 Arithmetic unary operators

Arithmetic Operators
(cont’ d.)
 Arithmetic unary operators
–
Performed on a single variable using unary operators
–