JavaScript Operators

From http://www.w3schools.com (Copyright Refsnes Data)

# JavaScript Operators

The operator = is used to assign values.

The operator + is used to add values.

The assignment operator = is used to assign values to JavaScript variables.

The arithmetic operator + is used to add values together.

    y=5;
    z=2;
    x=y+z;

The value of x, after the execution of the statements above is 7.

## JavaScript Arithmetic Operators

Arithmetic operators are used to perform arithmetic between variables and/or values.

Given that y=5, the table below explains the arithmetic operators:

Operator | Description | Example | Result
--- | --- | --- | ---
+ | Addition | x=y+2 | x=7
- | Subtraction | x=y-2 | x=3
* | Multiplication | x=y*2 | x=10
/ | Division | x=y/2 | x=2.5
% | Modulus (division remainder) | x=y%2 | x=1
++ | Increment | x=++y | x=6
-- | Decrement | x=--y | x=4

## JavaScript Assignment Operators

Assignment operators are used to assign values to JavaScript variables.

Given that x=10 and y=5, the table below explains the assignment operators:

Operator | Example | Same As | Result
--- | --- | --- | ---
= | x=y |  | x=5
+= | x+=y | x=x+y | x=15
-= | x-=y | x=x-y | x=5
*= | x*=y | x=x*y | x=50
/= | x/=y | x=x/y | x=2
%= | x%=y | x=x%y | x=0

## The + Operator Used on Strings

The + operator can also be used to add string variables or text values together.

To add two or more string variables together, use the + operator.

    txt1="What a very";
    txt2="nice day";
    txt3=txt1+txt2;

After the execution of the statements above, the variable txt3 contains "What a verynice day".

To add a space between the two strings, insert a space into one of the strings:

    txt1="What a very ";
    txt2="nice day";
    txt3=txt1+txt2;

or insert a space into the expression:

    txt1="What a very";
    txt2="nice day";
    txt3=txt1+" "+txt2;

After the execution of the statements above, the variable txt3 contains:

"What a very nice day"

## Adding Strings and Numbers

Look at these examples:

    x=5+5;
    document.write(x);

    x="5"+"5";
    document.write(x);

    x=5+"5";
    document.write(x);

    x="5"+5;
    document.write(x);

Try it yourself.

The rule is:

If you add a number and a string, the result will be a string.

From http://www.w3schools.com (Copyright Refsnes Data)