JavaScript Operators

General Comments:  The comparison operators compare two items and return a value of "true" if the conditions are true.

Returns a true value if the items are the same

Returns the value "true" if the counter's value is currently equal to the number 10

Returns a true value if the items are not the same

Returns the value "true" if the counter's value is any value except the number 10

Returns a true value if the item on the left is greater than the item on the right

Returns the value "true" if the counter's value is larger than the number 10

Returns a true value if the item on the left is equal to or greater than the item on the right

Returns the value "true" if the counter's value is equal to or larger than the number 10

Returns a true value if the item on the left is less than the item on the right

Returns the value "true" if the counter's value is smaller than the number 10

Returns a true value if the item on the left is equal to or less than the item on the right

Returns the value "true" if the counter's value is equal to or less than the number 10

General Comments:  The computational operators perform a mathematical function on a value or values, and return a single value.

Adds two values together

Returns the sum of the counter plus 2

Subtracts one value from another

Returns the sum of the counter minus 2

Multiplies two values

Returns the result of the variable times 10

Divides the value on the left by the one on the right and returns the result

Divides the current value of the counter by 2 and returns the result

Increments the value, and then returns the result

Looks at the current value of the counter, increments it by one, and then returns the result. If the counter has a value of 3, this equation returns the value of 4.

Returns the value, and then increments the value

Returns the value of the counter, then increments the counter. If the counter has a value of 3, this equation returns the value of 3, then sets the counter value to 4.

Decreases the value, and then returns the result

Looks at the current value of the counter, decreases it by one, and then returns the result. If the counter has a value of 7, this equation returns the value of 6.

Returns the value, and then decreases the value

Returns the value of the counter, then decrease the counter value. If the counter has a value of 7, this equation returns the value of 7, then sets the counter value to 6.

General Comments:  The logical operators evaluate expressions and then return a true or false value based on the result.

Looks at two expressions and returns a value of "true" if both expressions are true.

Compares the value of the day and the value of the date. If it is true that today is a Friday and if it is also true that the date is the 13th, then an alert box pops up with the message "Are You Superstitious?"

Looks at two expressions and returns a value of "true" if either one—but not both—of the expressions are true.

Compares the value of the day and the value of the date. If it is true that today is a Friday and if it is also true that the date is the 13th, then an alert box pops up with the message "Are You Superstitious?" If both are not true, the script moves onto the next line of code...

Which compares the value of the day and the value of the date. If either one—but not both—is true, then an alert box pops up with the message "Aren't you glad it isn't Friday the 13th?"