See image below, why is it the combined height of two labels (brown) different with the height of the label (red)?

Question

I just cut the original string \\nfoo\\n\\nbar\\n\\nfoo\\n\\nbar\\n into two different strings \\nfoo\\n\\nbar\\n and \\nfoo\\n\\nbar\\n . The cut strings will be set into its dedicated label. I was expecting that the combined height of the two labels would just be the same with a label that has the original string. Can you guide me into something that explains this? Is there a way to make the combined two labels the same with the one label without adding/deleting a character from the cut strings?

Playground

import PlaygroundSupport
import Foundation
import UIKit

PlaygroundPage.current.needsIndefiniteExecution = true

let viewWidth: CGFloat = 100.0

func createLabel(_ text: String, _ backgroundColor: UIColor = .white) -> UILabel {
    let label = UILabel()
    label.text = text
    label.numberOfLines = 0
    label.backgroundColor = backgroundColor
    label.textColor = .black
    label.sizeToFit()
    label.frame.size.width = viewWidth
    return label
}

let view = UIView(frame: CGRect(x: 0, y: 0, width: viewWidth, height: 1000))
view.backgroundColor = .white

let label1 = createLabel("\nfoo\n\nbar\n", .green)
let label2 = createLabel("\nfoo\n\nbar\n", .blue)
let label3 = createLabel("\nfoo\n\nbar\n\nfoo\n\nbar\n", .red)
let label4 = createLabel("\nfoo\n\nbar\n", .brown)
let label5 = createLabel("\nfoo\n\nbar\n", .brown)
label2.frame.origin.y = label1.frame.maxY
label3.frame.origin.y = label2.frame.maxY
label4.frame.origin.y = label3.frame.maxY
label5.frame.origin.y = label4.frame.maxY

view.addSubview(label1)
view.addSubview(label2)
view.addSubview(label3)
view.addSubview(label4)
view.addSubview(label5)

PlaygroundPage.current.liveView = view

/*
\nfoo\n\nbar\n
\nfoo\n\nbar\n
*/

Answer 1

when you combine the label4 and label5 that way, you have three new line,

the label4 should be let label4 = createLabel("\\nfoo\\n\\nbar", .brown)

remove \\n at the end.