Javascript - 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.
The value of x, after the execution of the statements above is 7.
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 |
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 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"
The rule is: If you add a number and a string, the result will be a string!
JavaScript Adding String and Numbers 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);
