iOS 获取图片路径的后缀/获取字符串的后缀

//判断是图片还是文字

NSString * urlString = @"
http://192.168.1.254/upload/savepicture/20160615/74841465953236815.jpg ";

NSString *fileName = [urlString
pathExtension];

NSLog(@"%@",fileName);

if([fileName isEqualToString:@"jpg"]||[fileName
isEqualToString:@"gif"]||[fileName
isEqualToString:@"png"]||[fileName
isEqualToString:@"jpeg"]||[fileName
isEqualToString:@"bmp"]){

       //是图片

    }else{

       //是文字

    }