What will happen if you remove optionals from Swift…

This would lead to a significant reduction in code safety. Many operations would become potentially unsafe, as the compiler would not be able to guarantee the presence of a value.

Removal of Optional Chaining (?) and Forced Unwrapping (!). The syntax for working with optionals would become invalid.
Need for constant nil checks. Developers would have to manually write if conditions for each operation with a potentially missing value, greatly increasing boilerplate code and complexity.
Increased risk of crashes. Without compiler guarantees about the presence of a value, attempting to access nil would lead to runtime errors.
Lack of elegant solutions for asynchronous operations. Handling results of asynchronous operations that may fail (returning nil) would become cumbersome.
Complication of working with Objective-C APIs. Many Objective-C methods return nil to indicate failure or absence of a value. Interoperability would become less safe.

Example code before and after (hypothetically):

Before:

var optionalString: String? = "Hello"
let length = optionalString?.count // Optional chaining

After (hypothetically):

var nonOptionalString: String // Now all variables must have a value upon initialization or be explicitly checked
var potentiallyNilStringFromSomewhere: String

// Instead of optional chaining, you would have to write:
if someFunctionCouldReturnNil() {
    // Error handling
} else {
    potentiallyNilStringFromSomewhere = ... // Assign a value
    let length = potentiallyNilStringFromSomewhere.count // Potential crash if the value is actually nil
}

// Or like this, if `nil` still existed in the language but without compiler support:
if potentiallyNilStringFromSomewhere != nil {
    let length = potentiallyNilStringFromSomewhere!.count // Dangerous forced unwrapping
} else {
    // Handle nil
}

Thus, the code would become more error-prone at runtime, less readable, and more difficult to maintain. Optionals are a key mechanism in Swift for ensuring type safety and combating Null Pointer Exceptions.

What will happen if you remove optionals from Swift?