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swiftnspredicate

How to use NSPredicate to return true?

Here is my code:

let newPredicate = NSPredicate(format: "true == %@")        
let y = newPredicate.evaluate(with: true)

print(y)

It always returns false.

How to use NSPredicate to return true?

Solution

  • The %@ placeholder is for arguments passed to the NSPredicate(format:) call, like this:

    let newPredicate = NSPredicate(format: "true == %@", true)

    If you want to use the object passed to evaluate(with:), use self:

    let newPredicate = NSPredicate(format: "true == self")
let y = newPredicate.evaluate(with: true)
print(y)