Multiple lines of text in UILabel

Set the line break mode to word-wrapping and the number of lines to 0:

// Swift
textLabel.lineBreakMode = .byWordWrapping
textLabel.numberOfLines = 0

// Objective-C
textLabel.lineBreakMode = NSLineBreakByWordWrapping;
textLabel.numberOfLines = 0;

// C# (Xamarin.iOS)
textLabel.LineBreakMode = UILineBreakMode.WordWrap;
textLabel.Lines = 0;  

Restored old answer (for reference and devs willing to support iOS below 6.0):

textLabel.lineBreakMode = UILineBreakModeWordWrap;
textLabel.numberOfLines = 0;

On the side: both enum values yield to 0 anyway.

In IB, set number of lines to 0 (allows unlimited lines)

When typing within the text field using IB, use "alt-return" to insert a return and go to the next line (or you can copy in text already separated out by lines).

Use this to have multiple lines of text in UILabel:

textLabel.lineBreakMode = NSLineBreakByWordWrapping;
textLabel.numberOfLines = 0;

Swift:

textLabel.lineBreakMode = .byWordWrapping
textLabel.numberOfLines = 0

Method 1:

extension UILabel {//Write this extension after close brackets of your class
    func lblFunction() {
        numberOfLines = 0
        lineBreakMode = .byWordWrapping//If you want word wraping
        //OR
        lineBreakMode = .byCharWrapping//If you want character wraping
    }
}

Now call simply like this

myLbl.lblFunction()//Replace your label name 

EX:

Import UIKit

class MyClassName: UIViewController {//For example this is your class. 

    override func viewDidLoad() {
    super.viewDidLoad()

        myLbl.lblFunction()//Replace your label name 

    }

}//After close of your class write this extension.

extension UILabel {//Write this extension after close brackets of your class
    func lblFunction() {
        numberOfLines = 0
        lineBreakMode = .byWordWrapping//If you want word wraping
        //OR
        lineBreakMode = .byCharWrapping//If you want character wraping
    }
}

Method 2:

Programmatically

yourLabel.numberOfLines = 0
yourLabel.lineBreakMode = .byWordWrapping//If you want word wraping
//OR
yourLabel.lineBreakMode = .byCharWrapping//If you want character wraping

Method 3:

Through Story board

To display multiple lines set 0(Zero), this will display more than one line in your label.

If you want to display n lines, set n.

See below screen.

If you want to set minimum font size for label Click Autoshrink and Select Minimum Font Size option

See below screens

Here set minimum font size

EX: 9 (In this image)

If your label get more text at that time your label text will be shrink upto 9

Swift 4:

label.lineBreakMode = .byWordWrapping

label.numberOfLines = 0

label.translatesAutoresizingMaskIntoConstraints = false

label.preferredMaxLayoutWidth = superview.bounds.size.width - 10 

Oh, in 2021 I'm trapped by a label text unable to change lines for 1 hour, then realize I forget to set label's width, WTF.

let stepLabel: UILabel = {
    let label = UILabel()
    label.translatesAutoresizingMaskIntoConstraints = false
    label.textAlignment = .center
    label.lineBreakMode = .byWordWrapping
    label.numberOfLines = 0
    label.text = "Put your device and computer under same Wi-Fi network."
    
    return label
}()

override func viewDidLoad() {
    super.viewDidLoad()
    
    view.backgroundColor = .white
    view.addSubview(stepLabel)

    NSLayoutConstraint.activate([
        stepLabel.centerXAnchor.constraint(equalTo: view.centerXAnchor),
        stepLabel.centerYAnchor.constraint(equalTo: view.centerYAnchor),
        stepLabel.widthAnchor.constraint(equalTo: view.widthAnchor, multiplier: 0.7)
    ])
}

On C#, this worked for me inside UITableViewCell.

        UILabel myLabel = new UILabel();
        myLabel.Font = UIFont.SystemFontOfSize(16);
        myLabel.Lines = 0;
        myLabel.TextAlignment = UITextAlignment.Left;
        myLabel.LineBreakMode = UILineBreakMode.WordWrap;
        myLabel.MinimumScaleFactor = 1;
        myLabel.AdjustsFontSizeToFitWidth = true;

       myLabel.InvalidateIntrinsicContentSize();
       myLabel.Frame = new CoreGraphics.CGRect(20, mycell.ContentView.Frame.Y + 20, cell.ContentView.Frame.Size.Width - 40, mycell.ContentView.Frame.Size.Height);
       myCell.ContentView.AddSubview(myLabel);

I think the point here is:-

            myLabel.TextAlignment = UITextAlignment.Left;
            myLabel.LineBreakMode = UILineBreakMode.WordWrap;
            myLabel.MinimumScaleFactor = 1;
            myLabel.AdjustsFontSizeToFitWidth = true;