| // Taken from https://en.wikipedia.org/wiki/JavaScript |
| |
| // Declares a function-scoped variable named `x`, and implicitly assigns the |
| // special value `undefined` to it. Variables without value are automatically |
| // set to undefined. |
| var x; |
| |
| // Variables can be manually set to `undefined` like so |
| var x2 = undefined; |
| |
| // Declares a block-scoped variable named `y`, and implicitly sets it to |
| // `undefined`. The `let` keyword was introduced in ECMAScript 2015. |
| let y; |
| |
| // Declares a block-scoped, un-reassignable variable named `z`, and sets it to |
| // a string literal. The `const` keyword was also introduced in ECMAScript 2015, |
| // and must be explicitly assigned to. |
| |
| // The keyword `const` means constant, hence the variable cannot be reassigned |
| // as the value is `constant`. |
| const z = "this value cannot be reassigned!"; |
| |
| // Declares a variable named `myNumber`, and assigns a number literal (the value |
| // `2`) to it. |
| let myNumber = 2; |
| |
| // Reassigns `myNumber`, setting it to a string literal (the value `"foo"`). |
| // JavaScript is a dynamically-typed language, so this is legal. |
| myNumber = "foo"; |
| |
| const target = "foo"; |
