What will happen in the program if all object references are used as weak?

If all references to objects in a program are weak, then the objects will not be held in memory by strong references and can be deallocated by the garbage collector at any moment when there are no strong references to them.

This means that objects can be released immediately after creation or after they go out of scope if there are no strong references.

In iOS (Swift/Objective-C), weak references are used to prevent retain cycles, but if an object is not held by any strong reference, it will be deinitialized.

Example:

class Person {
    var name: String
    init(name: String) { self.name = name }
    deinit { print("Person deinitialized") }
}

weak var weakPerson: Person? = Person(name: "Alex")
// After this line, the Person object can be immediately deallocated since there are no strong references

Thus, if all references are weak, objects will not live long and can be deallocated immediately, leading to unexpected behavior of the program.