Showing posts with label Operators. Show all posts
Showing posts with label Operators. Show all posts

Triple equals in JavaScript
11:15 PM - Posted by Vipin C - 0 comments
I think I'm a pretty decent javascript programmer, so it's always refreshing to learn something new in a language I'm so familiar with! I recently had some time to watch those great lectures from Doug Crockford at YUI Theatre, and noticed lots of === in the code.
That's right, it's not a typo, but 3 equal signs, and it means equality without type coersion. In other words, if using the triple equals, the values must be equal in type as well.
e.g. 
0==false   // true
0===false  // false, because they are of a different type
1=="1"     // true, auto type coersion
1==="1"    // false, because they are of a different type
Another handy tool in my javascript bag of tricks, as recommended by Mr father of javascript himself!


Conditional Operator
11:12 PM - Posted by Vipin C - 0 comments

JavaScript also contains a conditional operator that assigns a value to a variable based on some condition.

Syntax

variablename=(condition)?value1:value2

Example

greeting=(visitor=="PRES")?"Dear President ":"Dear ";

If the variable visitor has the value of "PRES", then the variable greeting will be assigned the value "Dear President " else it will be assigned "Dear".



Logical Operators
11:11 PM - Posted by Vipin C - 0 comments

Logical operators are used to determine the logic between variables or values.

Given that x=6 and y=3, the table below explains the logical operators:

Operator Description Example
&& and (x < 10 && y > 1) is true
|| or (x==5 || y==5) is false
! not !(x==y) is true