JS Practice — Built-in Objects

Object.seal() — writable properties remain writable

📖 Usage Example

// Prevent adding/removing properties but allow value changes
const obj = Object.seal({ x: 1 })
obj.x = 99     // allowed — value can change
delete obj.x   // silently ignored
obj.x          // → 99

Use Object.seal() to prevent adding or deleting properties on an object while still allowing existing values to be updated.

Object.seal() — values can still change

Unlike Object.freeze(), sealing does NOT make properties non-writable. You can still change values of existing properties.

Challenge: Show that a sealed object's properties can still be updated.

💡 Hints (1)

• seal = non-extensible + non-configurable, but writable values still change