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.
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.
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