Interaction methods: alert, prompt, confirm & Type Conversions

🥑 alert

🥑 prompt

🥑 confirm

🥑 String Conversion

🥑 Numeric Conversion

🥑 Boolean Conversion

The alert() method displays a message in a dialog box with an OK button, prompting the user to acknowledge the message.

For example:

alert("Welcome to my 100 days of JS challenge!");

The prompt() method displays a dialog box with a message and an input field, allowing the user to enter data. It returns the text entered by the user, or null if the user clicks Cancel.

For example:

let name = prompt("Hello! I'm lassie. What's your name?");
console.log("Hello, " + name + "!");

The confirm() method displays a dialog box with a message and OK and Cancel buttons, allowing the user to confirm or cancel an action. It returns true if the user clicks OK and false if the user clicks Cancel.

For example:

let result = confirm("Are you sure you want to delete this item?");
if (result) {
  console.log("Item deleted successfully.");
} else {
  console.log("Deletion canceled.");
}

We use these interaction methods in JavaScript to provide feedback to users and prompt them for input or confirmation.

The process of converting values from one data type to another is Type conversion.

String conversion occurs when a value is converted to a string data type.

For example:

let num = 42;
let str = String(num); // Explicit string conversion using String() function
console.log(typeof str); // Output: string

Numeric conversion occurs when a value is converted to a numeric data type. This can happen using - Number() or parseInt()

The Number() function converts a value to a numeric data type (integer or floating-point number).

For example:

let num1 = Number("42"); // Convert string to number
let num2 = Number("3.14"); // Convert string to number
let num3 = Number(true); // Convert boolean to number (true -> 1, false -> 0)
console.log(num1); // Output: 42
console.log(num2); // Output: 3.14
console.log(num3); // Output: 1

The parseInt() function parses a string and returns an integer. It stops parsing when it encounters a non-digit character.

For example:

let num1 = parseInt("42"); // Parse string to integer
let num2 = parseInt("3.14"); // Parse string to integer (decimal part is ignored)
let num3 = parseInt("42px"); // Parse string to integer (non-digit character stops parsing)
console.log(num1); // Output: 42
console.log(num2); // Output: 3
console.log(num3); // Output: 42

The parseFloat() function in JavaScript is used to parse a string and convert it to a floating-point number (a number with decimal points).

For example:

let priceString = "Price: $24.99"; // String containing a price
let price = parseFloat(priceString); // Extract the floating-point number from the string
console.log(price); // Output: 24.99

Boolean conversion occurs when a value is converted to a boolean data type (true or false). This can happen implicitly in certain contexts, such as in conditional statements (if, while, etc.), or explicitly using the Boolean() function.

For example:

let str = "hello";
let bool = Boolean(str); // Explicit boolean conversion using Boolean() function
console.log(bool); // Output: true (non-empty string is converted to true)