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Sazzad Hissain Khan
Sazzad Hissain Khan

Reputation: 40156

Objective C - Called object type 'BOOL' (aka 'bool') is not a function or function pointer

Working on a legacy hybrid iOS project. Created one new Swift util class in ConsentManager.swift, like below,

import Foundation

public class ConsentManager: NSObject {
    @objc static let sharedInstance = ConsentManager()
    @objc private override init() {}
    @objc public func isDataPermissionConsentRequired() -> Bool
    {
        …
        return value; // based on logic
    }
}

Called the method from another objc class, ConsentChecker.m like,

@interface ConsentChecker ()
{
}
@end

@implementation ConsentChecker
-(void)checkConsent {
    
    // GETTING ERROR IN THE FOLLOWING LINE
    if (ConsentManager.sharedInstance.isDataPermissionConsentRequired())  { 
        …
    }
}
@end

Getting compiler error:

Called object type 'BOOL' (aka 'bool') is not a function or function pointer

Why and how to resolve it?

Upvotes: 0

Views: 1037

Answers (3)

Sahidul Islam
Sahidul Islam

Reputation: 139

If u want to call swift function on obj-c class you use to obj-c syntax

Correct Syntax is:

if ([ConsentManager.sharedInstance isDataPermissionConsentRequired])  {
    // Write logic here
}

Upvotes: 0

Itai Ferber
Itai Ferber

Reputation: 29764

The reason you're hitting this is that methods in Objective-C which take no arguments may be called implicitly using dot syntax similar to Swift's, but not exactly like it. A method declared like

// Inside of SomeClass
- (BOOL)someMethod { /* return something */ }

can be called either as

SomeClass *instance = ...

// Traditional Obj-C syntax:
BOOL value = [instance someMethod];

or

// Dot syntax accessor:
BOOL value = instance.someMethod;

Note that the dot syntax version does not use parentheses to denote the call. When you add parentheses like you would in Swift, Obj-C determines that you are trying to call the returned value from the method as if it were a function:

instance.someMethod();

// equivalent to:

BOOL value = [instance someMethod];
value(); // <- Called object type 'BOOL' (aka 'bool') is not a function or function pointer

You cannot call a BOOL like you can a function, hence the error.

@Dávid offers the more traditional Obj-C syntax for calling this method, but alternatively, you can simply drop the parentheses from your call:

if (ConsentManager.sharedInstance.isDataPermissionConsentRequired) {

Objective-C-ism note:

Dot syntax is most idiomatically used for method calls which appear like properties (e.g. boolean accessors like your isDataPermissionConsentRequired), even if the method might need to do a little bit of work to return that value (think: computed properties in Swift).

For methods which perform an action, or which return a value but might require a significant amount of work, traditional method call syntax is typically preferred:

// Prefer:
[instance doTheThing];
NSInteger result = [instance performSomeExpensiveCalculation];

// over:
instance.doTheThing;
NSInteger result = instance.performSomeExpensiveCalculation;

Upvotes: 4

David Pasztor
David Pasztor

Reputation: 54706

The Obj-C syntax for executing methods is different from Swift's dot syntax.

This is the correct syntax:

if ([ConsentManager.sharedInstance isDataPermissionConsentRequired])  {

Upvotes: 2

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