Javascript Data-Types | strings, string-literals, boolean, null and numbers
JavaScript is a loosely typed language which means we can store any type of data in a variable without specifying its type.
Example
DataType types
String
Strings are a sequence of characters wrapped in double or single quotes.
Below ways, we can assign Strings
String Concatenation
We can join variables to strings using `+` Operator or use string literal which is the best way.
Using +
Operator
Using String Literals`
Numbers
Adding two numbers
let a=5,b=7; let z=a+b; alert(z);
Add number and string
let a=5; let b="7"; let z=a+b; alert(z); //output 57
null type
If we don’t want to initialize the value to variable than we can use null which basically means nothing.
let designation=null alert(designation); // outputs null
undefined type
If we declare variable but don’t initialize its value than the value of the variable will be undefined
.
let name; alert(name); //outputs undefined
Boolean Date-Type
Boolean types have two values that are true
or false
. We can also assign 1 which means true and 0 which means false.
let has_completed_howework=true; alert(has_completed_howework); //outputs true
We can use this for conditional checking
let has_completed_howework=true; if(has_completed_howework==true){ alert("Student has completed homework"); }else{ alert("Student has not completed homework"); }
Objects
Objects are special datatypes using them we can store different variable values with different data types. Objects will be covered in the coming tutorial in detail.
Other Javascript Posts
- Javascript Strings – Properties and Methods with examples
- Javascript Numbers | Assignment, Type Checking and NaN