TypeScript Boolean Data Type

Same like JavaScript, TypeScript also supports Boolean values. In TypeScript, the boolean data type is useful to define variables to accept only Boolean values (true/false).

TypeScript Boolean Type Syntax

Following is the syntax of defining the variables with boolean type in typescript.


[Keyword] [Variable Name]: [boolean] = [Value];

[Keyword] [Variable Name]: [boolean];

If you observe the above syntax, we added a boolean datatype after the variable name to tell the compiler that the boolean type of data the variable can hold.


  • [Keyword] - It’s a keyword of the variable either var, let or const to define the scope and usage of variables.
  • [Variable Name] - Its name of the variable to hold the values in our application.
  • [boolean] - It’s a boolean type of data the variable can hold.
  • [Value] - Assigning a required value to the variable.

Now, we will learn how to use boolean data types in TypeScript with examples.

TypeScript Boolean Data Type Example

Following is the example of defining the variables with boolean data type in typescript.


var isVerified: boolean = true;

var isDone: Boolean = false;

console.log(isVerified); // true

console.log(isDone); // false

If you observe the above boolean type example, we defined the variables with lower case boolean type and upper case Boolean type. Here, the lower case boolean is a primitive type and the upper case Boolean is an object type. In TypeScript, it’s always recommended to use primitive lower case boolean type.


This is how we can use boolean type in typescript to define the variables to accept only boolean values based on our requirements.