How to check if a variable is a string in JavaScript?

Hello everyone! I'm new to JavaScript and ran into a problem. I have a function that should only work with string values. If I pass a number or an object, everything breaks. I'm trying to check the variable type using typeof, but the results confuse me. Here's an example of my code: ```javascript function processInput(input) { if (typeof input === 'string') { console.log('This is a string, length: ' + input.length); } else { console.log('This is not a string!'); } } processInput('Hello'); // Works: "This is a string, length: 5" processInput(42); // Works: "This is not a string!" processInput(new String('Test')); // Outputs "This is not a string!" — but I expected it to be a string! processInput(null); // Outputs "This is not a string!" — ok processInput(undefined); // Outputs "Th