= 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:



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:Advertisement

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);