For example,

5 + 7 = 12

The + (plus sign) here, is an operator (an arithmetic operator), the number 5 is the left operand and the value 7 is the right operand.

In JavaScript, you can assign the data values (or the operands) to variables and apply an operator to get a result, or you can simply use numbers along with an operator and get the result. For example,

<script> var a = 5; var b = 7; var c = a + b; alert (c); // Using ES6 features. // let a = 5; // let b = 7; // let c = a + b; // alert (c); // the answer is 12. </script>

Or, simply use numbers with the + operator.

var result = 5 + 7; alert (result); // Using ES6 features. // let result = 5 + 7; // alert (result); // its 12 again.

**Note**: The + operator can also be used to concatenate (or add) strings. I have explained about it here.

Its basic math and we have done this before. Therefore, lets begin with the Arithmetic Operators.

## JavaScript Arithmetic Operators

Operator | Description |
---|---|

+ | Addition |

- | Subtraction |

* | Multiplication |

/ | Division |

% | Modulus (gives the remainder obtained by dividing two operands or numbers) More examples using modulus operator |

++ | Increment (It will increase value by 1) |

-- | Decrement (it will decrease the value by 1) |

## Using + Operator to Concatenate Values

The + (plus) operator is often used to add two or more numbers. However, it can also be used to concatenate two values of different data types. For example,

var name = 'alpha';

var age = 27;

alert (name + ' is ' + age + ' years old');

// Using ES6

let name = 'alpha';

let age = 27;

alert (name + ' is ' + age + ' years old');

We can use the + on different data types to get different results. For example,

// Concatenating two string values. let a = 'arun ', b = 'banik'; alert (a + b); // the result is arun banik // or // Concatenating a string with number. let x = 3, y = ' dimension'; alert (x + y); // the result is 3 dimension.

Interesting isn't?

**Note**: Be careful while using the + operator. The results can vary.

Can you spot the difference between the two examples below?

1) let a, b; a = 5; b = 7; document.getElementById('result').innerHTML = 'a + b ' + ' = ' + (a + b); 2) let a, b; a = 5; b = 7; document.getElementById('result').innerHTML = 'a + b ' + ' = ' + a + b;

Ok, let’s move on to the next set of operators.

## JavaScript Comparison Operators

Comparison operators in JavaScript are used to compare two given values, and the result is returned in a Boolean value, that is, true or false.

Operator | Description |
---|---|

== | equal to Try it |

=== | compares equal value with equal type Try it |

!= | not equal (compares two operands that are not equal) Try it |

> | greater than Try it |

< | less than Try it |

>= | greater than or equal to Try it |

<= | less than or equal to Try it |

## JavaScript Conditional Operator

JavaScript also has a conditional operator called the ternary operator. It assigns a value to a varible after satisfying a conditon. Its actually works like the if...else statement. I have explained about ternary operator in detail here.

### Syntax

Condition ? first_expression : second_expression

## JavaScript Logical Operators

The logical operators are used to compare two or more conditions.

Operator | Description |
---|---|

&& | the logical AND operator Try it |

|| | the logical OR operator Try it |

! | the logical NOT operator Try it |

## JavaScript Assignment Operators

Assignment operators in JavaScript are used to assign values to variables. For example,

let a = 5;

Here, I have assigned the value 5 to the variable a using the = (or, equal assignment) operator. It can also be a = b, assigning value to a variable from another variable. There are many more assignment operators like this.

Operator | Description |
---|---|

= | Assign right operand value to the left operand. For example, a = 5; or a = b; Don’t get confused with "=" to "==" (see Comparison Operators) Try it |

+= | Sum of two right operand values is assigned to the left operand. For example, a = a + b; or a += b; Try it |

-= | Subtract right operand value from the left operand and assign the result to the left operand. For example, a -= 2; or a = a – 2; Try it |

*= | Multiply right and left operand values and assign the result to the left operand. For example, a *= 5; or a = a * 5; or a = a * b; Try it |

/= | Divide left operand value with the right operand and assign the result to the left operand. For example, a /= 5; or a = a / 5; or a = a / b; Try it |

%= | Get the modulus of left operand, divide it by right operand and assign the result to the left operand. For example, a %= 2; or a %= b; or a = a % b; See more examples Try it |