How to align UILabel text from bottom?

Here are two ways of doing that...

1. First set numberOfLines to 0 and then use sizeToFit property of UILabel so your UILabel display with its contentSize.

yourLabel.numberOfLines = 0;

[yourLabel sizeToFit];

See more information from this link: Vertically align text within a UILabel

2. Another option is to take UITextField instead of UILabel and set userInteractionEnabled to NO like below...

[yourTextField setUserInteractionEnabled:NO];

and then set the contentVerticalAlignment property to bottom like below...

[yourTextField setContentVerticalAlignment:UIControlContentVerticalAlignmentBottom];

UPDATE

Also, with UITextField, we can't achieve multiple lines. So instead we can use UITextView and set its userInteractionEnabled to NO. Then, use the code below to make it bottom aligned.

CGFloat topCorrect = ([label bounds].size.height - [label contentSize].height);
topCorrect = (topCorrect <0.0 ? 0.0 : topCorrect);
label.contentOffset = (CGPoint){.x = 0, .y = -topCorrect};

i only set a bottom constraint to the super view in IB which works for me without using code and also number of Lines for a maximum constraint.

Swift 4.2 version using the contentMode property to set top and bottom:

class VerticalAlignedLabel: UILabel {
    
    override func drawText(in rect: CGRect) {
        var newRect = rect
        switch contentMode {
        case .top:
            newRect.size.height = sizeThatFits(rect.size).height
        case .bottom:
            let height = sizeThatFits(rect.size).height
            newRect.origin.y += rect.size.height - height
            newRect.size.height = height
        default:
            ()
        }
        
        super.drawText(in: newRect)
    }
}

Then setup your label like that:

let label = VerticalAlignedLabel()
label.contentMode = .bottom

Subclass UILabel

@interface Label : UILabel

@end

Then override drawTextInRect like so

@implementation Label

- (void)drawTextInRect:(CGRect)rect
{
    if(alignment == top) {

        rect.size.height = [self sizeThatFits:rect.size].height;
    }

    if(alignment == bottom) {

        CGFloat height = [self sizeThatFits:rect.size].height;

        rect.origin.y += rect.size.height - height;
        rect.size.height = height;
    }

    [super drawTextInRect:rect];
}

@end