How to count the number of lines in an Objective-C string (NSString)?

Question

I want to count the lines in an NSString in Objective-C.

  NSInteger lineNum = 0;
  NSString *string = @\"abcde\\nfghijk\\nlmnopq\\nrstu\";
  NSInteger lengt         


        

Answer 1

If you want to take into account the width of the text, you can do this with TextKit (iOS7+):

func numberOfLinesForString(string: String, size: CGSize, font: UIFont) -> Int {
    let textStorage = NSTextStorage(string: string, attributes: [NSFontAttributeName: font])

    let textContainer = NSTextContainer(size: size)
    textContainer.lineBreakMode = .ByWordWrapping
    textContainer.maximumNumberOfLines = 0
    textContainer.lineFragmentPadding = 0

    let layoutManager = NSLayoutManager()
    layoutManager.textStorage = textStorage
    layoutManager.addTextContainer(textContainer)

    var numberOfLines = 0
    var index = 0
    var lineRange : NSRange = NSMakeRange(0, 0)
    for (; index < layoutManager.numberOfGlyphs; numberOfLines++) {
        layoutManager.lineFragmentRectForGlyphAtIndex(index, effectiveRange: &lineRange)
        index = NSMaxRange(lineRange)
    }

    return numberOfLines
}