Slide 1

Operations on Numbers

Assign values to variables and add them together:

 let x = 5;         // assign the value 5 to x
 let y = 2;         // assign the value 2 to y
 let z = x + y;     // assign the value 7 to z (5 + 2)

The assignment operator (=) assigns a value to a variable.

 let x = 10;

The addition operator (+) adds numbers:

 let x = 5;
 let y = 2;
 let z = x + y;

The multiplication operator (*) multiplies numbers.

 let x = 5;
 let y = 2;
 let z = x * y;

Slide 2

JavaScript Arithmetic Operators

Arithmetic operators are used to perform arithmetic on numbers:

Slide 3

JavaScript Assignment Operators

Assignment operators assign values to JavaScript variables.

The addition assignment operator (+=) adds a value to a variable.

let x = 10; x += 5; //Output is 15

Slide 4

Operations on Strings

The + operator can also be used to add (concatenate) strings.

Example:-

 let text1 = "John";
 let text2 = "Doe";
 let text3 = text1 + " " + text2;

The result of txt3 will be:

 John Doe

The += assignment operator can also be used to add (concatenate) strings:

Example:

 let text1 = "What a very ";
 text1 += "nice day";

The result of txt1 will be:

 What a very nice day

 When used on strings, the + operator is called the concatenation operator.

Slide 5

Adding Strings and Numbers

Adding two numbers, will return the sum, but adding a number and a string will return a string:

 let x = 5 + 5;
 let y = "5" + 5;
 let z = "Hello" + 5;

The result of x, y, and z will be:

 10
 55
 Hello5

 If you add a number and a string, the result will be a string!