In JavaScript, numbers can be represented in several ways, including integers, floating-point numbers, and BigInts for very large numbers. JavaScript follows the standard arithmetic operations such as addition, subtraction, multiplication, and division. It also supports more complex operations like exponentiation, modulo operation, and handling of special numeric values such as Infinity, -Infinity, and NaN (Not a Number).
// Basic Arithmetic Operations
console.log('Addition: ', 5 + 3); // Outputs: 8
console.log('Subtraction: ', 10 - 2); // Outputs: 8
console.log('Multiplication: ', 4 * 2); // Outputs: 8
console.log('Division: ', 16 / 2); // Outputs: 8
// Exponentiation (ES2016)
console.log('Exponentiation: ', 2 ** 3); // Outputs: 8
// Modulo operation - remainder of division
console.log('Modulo: ', 10 % 4); // Outputs: 2
// Special Numbers
console.log('Infinity: ', 1 / 0); // Outputs: Infinity
console.log('-Infinity: ', -1 / 0); // Outputs: -Infinity
console.log(
'NaN (result of undefined or erroneous operations): ',
Math.sqrt(-1)
); // Outputs: NaN
// BigInt (for very large numbers, append 'n' to the end of an integer)
console.log('BigInt: ', 1234567890123456789012345678901234567890n + 1n); // Outputs: 1234567890123456789012345678901234567891n-
document.body.innerHTML = "Addition:" 5 + 3; press Enter the console output is 'Addition: 8' the Browser is Addition: 8
This code demonstrates basic arithmetic operations, the use of exponentiation, modulo operation, handling of special numbers, and the use of BigInt for very large numbers. You can run these examples in the JavaScript console of your browser or in a Node.js environment.
The code snippet document.body.innerHTML = console.log("Addition:" 5 + 3); has a couple of issues:
- Syntax Error: There's a missing comma or plus sign between
"Addition:"and5. To concatenate the string and the result, you should use a plus sign (+) or a comma within theconsole.logfunction. However, since the intention seems to be to display the result in the browser's body, usingconsole.logis not necessary or correct in this context. - Misuse of
console.log: Theconsole.logfunction is used to log messages to the console; it does not return a value that can be assigned todocument.body.innerHTML. Instead, you should directly assign the concatenated string todocument.body.innerHTML.
document.body.innerHTML = console.log("Addition:" 5 + 3); VM3444:1 Uncaught SyntaxError: missing ) after argument listUnderstand this error document.body.innerHTML = (console.log("Addition:" 5 + 3)); VM3543:1 Uncaught SyntaxError: missing ) after argument listUnderstand this error let console.log("Addition:", 5 + 3) VM3
Here's the corrected code that displays the result in the browser:
document.body.innerHTML = 'Addition: ' + (5 + 3); // Output: Addition: 8
let myConsole = console.log('Addition:', 5 + 3); // Output: Addition: 8This code concatenates the string "Addition: " with the result of the addition 5 + 3 and then assigns this complete string to document.body.innerHTML, effectively displaying the result in the body of the webpage.
To perform mathematical operations on user input in JavaScript, follow these steps:
- Collect User Input: Use
prompt()to collect input or<input>elements in HTML for a more interactive approach. - Parse the Input: Convert the input string to a number using
parseInt(),parseFloat(), or the unary+operator, depending on the expected number format (integer or floating-point). - Perform Operations: Apply the desired mathematical operations on the parsed numbers.
- Display the Result: Show the result using
console.log(),alert(), or by updating the DOM for web pages.
- Collect input using
prompt()or from an<input>element. - Parse the input to a number.
- Perform the desired mathematical operation.
- Display the result.
This example demonstrates collecting two numbers from the user, performing addition, and displaying the result:
<!DOCTYPE html>
<html>
<body>
<!-- Input fields for numbers -->
<input type="text" id="number1" placeholder="Enter first number" />
<input type="text" id="number2" placeholder="Enter second number" />
<button onclick="addNumbers()">Add Numbers</button>
<p id="result"></p>
<script>
function addNumbers() {
// Collect input values
var num1 = document.getElementById('number1').value;
var num2 = document.getElementById('number2').value;
// Parse input to numbers
num1 = parseFloat(num1);
num2 = parseFloat(num2);
// Perform addition
var sum = num1 + num2;
// Display the result
document.getElementById('result').innerText = 'Result: ' + sum;
}
</script>
</body>
</html>This code provides a simple HTML form for user input and a button to trigger the addition. The result is displayed on the webpage. You can modify the addNumbers function to perform different mathematical operations as needed.
Note: " * and / calculate first", then " + and - calculate after", " * and / have the same priority", but calculate from left to right, (...) in the bracket calculate first
2 + 2 // Output: 4 10 - 3; // Output: 7 10 _ 3; // Output: 30 10 / 5; // Output: 2 2 + 2 + 2 // Output: 6 2.2 + 2.2 // Output: 4.4 10.90 _ 2 + 20.95 // Output: 42.75 10.90 _ 2 + 20.95 + 4.99 // Output: 47.74 1 + 1 _ 3 // Output: 4 2 _ 3 / 5 // Output: 1.2 2 _ 3 // Output: 6 6 / 5 // Output: 1.2 (1 + 1) _ 3 // Output: 6 20.95 + 7.99 _ 2 // Output: 36.93 36.93 * 0.1 // Output: 3.693
(20.95 + 7.99 _ 2) _ 0.1 // Output: 3.693
- Weird behavior of math in JavaScript 0.1 + 0.2 // Output: 0.30000000000000004 20.95 + 7.99 // Output: 28.939999999999998 (2099 + 799) / 100 // Output: 28.98 (2095 + 799) / 100 // Output: 28.94
- Math.round() Math.round(); // Output: NaN Math.round(2.2) // Output: 2 Math.round(2.8) // Output: 3 ((2095 + 799) _ 0.1) / 100 // Output: 2.894 Math.round((2095 + 799) _ 0.1) // Output: 289 Math.round((2095 + 799) * 0.1) / 100 // Output: 2.89
Please generate the below review and code example in javascript for the console:
- Numbers and Math
- Order of Operators, and Brackets (...)
- Calculated the numbers in final project
- Calculations using floats can be inaccurate
- Math.round()
- How to search for code on our own
JavaScript supports various mathematical operations. You can perform basic arithmetic operations directly with numbers.
console.log(5 + 3); // Addition, outputs: 8
console.log(10 - 2); // Subtraction, outputs: 8
console.log(4 * 2); // Multiplication, outputs: 8
console.log(16 / 2); // Division, outputs: 8JavaScript follows the standard order of operations, also known as PEMDAS (Parentheses, Exponents, Multiplication and Division, Addition and Subtraction).
console.log(2 + 3 * 2); // First multiplies, then adds, outputs: 8
console.log((2 + 3) * 2); // Parentheses first, then multiplication, outputs: 10In projects, you often calculate numbers using basic arithmetic operations, taking care of the order of operations.
let result = (10 + 5) * 2;
console.log(result); // Outputs: 30Due to the way JavaScript handles floating-point arithmetic, calculations can lead to precision issues.
console.log(0.1 + 0.2); // Outputs: 0.30000000000000004To deal with floating-point inaccuracies, you can use Math.round() to round numbers to the nearest integer.
console.log(Math.round(0.1 + 0.2)); // Outputs: 0, because 0.30000000000000004 rounds to 0
console.log(Math.round(2.5)); // Outputs: 3To find solutions or code examples, use search engines effectively. Use specific keywords related to your problem. For example, if you need to round a number in JavaScript, you can search for:
- "JavaScript round number to nearest integer"
- "How to use Math.round in JavaScript"
Using precise keywords helps in finding relevant documentation, tutorials, and code snippets.