⛔duplicate parameter not allowed in strict mode❗️
in "strict mode", duplicate parameters not allowed❗️
console.log("Howdy"); // Howdy
sayHi("Hello", "Hi"); // Hi
function sayHi(x, x) { // duplicate parameters
console.log(x);
}console.log("Howdy"); // ⭐️ never runs❗
// ⛔ SyntaxError:
// Duplicate parameter name not allowed in this context
// ↓
function sayHi(x, x) { // ⭐️ compile-time error
"use strict"; // ⭐️ strict mode
console.log(x);
}Last updated