Friday 1 April 2011

Operators


= is used to assign values.
+ 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:
OperatorDescriptionExampleResult
+Additionx=y+2x=7y=5
-Subtractionx=y-2x=3y=5
*Multiplicationx=y*2x=10y=5
/Divisionx=y/2x=2.5y=5
%Modulus (division remainder)x=y%2x=1y=5
++Incrementx=++yx=6y=6
x=y++x=5y=6
--Decrementx=--yx=4y=4
x=y--x=5y=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:
OperatorExampleSame AsResult
=x=y x=5
+=x+=yx=x+yx=15
-=x-=yx=x-yx=5
*=x*=yx=x*yx=50
/=x/=yx=x/yx=2
%=x%=yx=x%yx=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

The rule is: If you add a number and a string, the result will be a string!

Example

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

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

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

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

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