TypeScript variable types and basic operations

TypeScript Basic: Exercise-3 with Solution

Write a TypeScript program that declares variables of the following data types: number, string, boolean, and undefined. Assign values to them and perform basic operations.

Sample Solution:

TypeScript Code:

// Declare variables
let n1: number = 42;
let strVariable: string = "Hello, TypeScript!";
let boolVariable: boolean = true;
let undefinedVariable: undefined = undefined;

// Perform basic operations
const n2: number = 10;

// Addition
const sum: number = n1 + n2;
console.log("Sum:", sum);

// String concatenation
const concatenatedString: string = strVariable + " How are you?";
console.log("Concatenated String:", concatenatedString);

// Logical operation
const isTrue: boolean = boolVariable && true;
console.log("Logical AND:", isTrue);

// Check if undefined
if (undefinedVariable === undefined) {
    console.log("undefinedVariable is undefined.");
} else {
    console.log("undefinedVariable is defined.");
}

Explanations:

In the exercise above,

• Declare variables 'n1', 'strVariable', 'boolVariable', and 'undefinedVariable' with their respective data types.
• Assign values to these variables.
• Perform basic operations such as addition, string concatenation, and logical operations.
• Finally, check if the 'undefinedVariable' is 'undefined' and print a corresponding message.

Output:

"Sum:"
52
"Concatenated String:"
"Hello, TypeScript! How are you?"
"Logical AND:"
true
"undefinedVariable is undefined."

TypeScript Editor:

See the Pen TypeScript by w3resource (@w3resource) on CodePen.

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