How to fix undefined variable error in PHP?

Question

I have following codes and it shows some errors which are described below:

<?php 
$terms = wp_get_post_terms( $post->ID, array('competition', 'season') );
$term_slugs = wp_list_pluck( $terms, 'slug' );    
$season = wp_get_post_terms( $post->ID, 'season' );
$season_slugs = wp_list_pluck( $terms, 'slug' ); 
$args = array(
    'post_type' => array( 'football_fixture' ),
    'tax_query' => array(
      array(
      'taxonomy' => 'competition',
      'field' => 'slug',
      'terms' => $term_slugs
      ),
      array (
      'taxonomy' => 'season',
      'terms' => $season_slugs,
      'field' => 'slug')
    ),
    'meta_query' => array(
      array(
        'key'     => 'pb_match_status',
        'value'   => 'ft'
      ),
   )   
);

  $my_query = null;
  $my_query = new WP_Query($args);

  $temp_teams_home=array();
  $temp_teams_away=array();
  $winning_team=array();
  $losing_team=array();
  $drawn_team=array();
  $league_ids=array();
  $season_ids=array();
  $total_goals=[];

  while ($my_query->have_posts()) : $my_query->the_post();
    $temp_teams_home[] = get_post_meta( get_the_ID(), 'match_details_home_team', true );
    $temp_teams_away[] = get_post_meta( get_the_ID(), 'match_details_away_team', true );
    $home_team = get_post_meta( get_the_ID(), 'match_details_home_team', true );
    $away_team = get_post_meta( get_the_ID(), 'match_details_away_team', true );
    $home_goals = get_post_meta( get_the_ID(), 'pb_home_score', true );
    $away_goals = get_post_meta(get_the_ID(), 'pb_away_score', true );

    if($home_goals > $away_goals){
      $winning_team[]=$home_team;
      $losing_team[]=$away_team;      
    } 
    if($home_goals < $away_goals){
      $winning_team[]=$away_team;
      $losing_team[]=$home_team;
    } 
    if ($home_goals == $away_goals){
      $drawn_team[]=$home_team;
      $drawn_team[]=$away_team;
    }     

    $total_goals_scored[]=array($home_team=>$home_goals,$away_team=>$away_goals);
    $total_goals_condeded[]=array($home_team=>$away_goals,$away_team=>$home_goals);
  endwhile;

  $total_matches_played = array_count_values(array_merge($temp_teams_home,$temp_teams_away));
  $team_wins = array_count_values($winning_team);
  $team_loses = array_count_values($losing_team);
  $team_drawn = array_count_values($drawn_team);  
  $total_goals_scored_by_teams=get_single_team_total($total_goals_scored);
  $total_goals_condeded_by_teams=get_single_team_total($total_goals_condeded);

  $total_points=0;
  $team_points=[];
  $team_points2=[];
  $team_points3=[];
  foreach($team_wins as $tw_key=>$tw_val){
    $team_points[$tw_key]=$tw_val*3;
  }

  foreach($team_drawn as $tw_key=>$tw_val){
    $team_points2[$tw_key]=$tw_val*1;
  }

  $total_points_final = array();
  $total_points_final2 = array();
  foreach (array_keys($team_points + $team_points2) as $key) {
    $total_points_final[$key] = (isset($team_points[$key]) ? $team_points[$key] : 0) + (isset($team_points2[$key]) ? $team_points2[$key] : 0);
  }

  foreach($team_loses as $tw_key=>$tw_val){
    $team_points3[$tw_key]=$tw_val*0;
  }

  foreach (array_keys($total_points_final + $team_points3) as $key) {
    $total_points_final2[$key] = (isset($total_points_final[$key]) ? $total_points_final[$key] : 0) + (isset($team_points3[$key]) ? $team_points3[$key] : 0);
  }

  $result=generate_table_details($total_matches_played,$team_wins,$team_loses,$team_drawn,$total_goals_scored_by_teams,$total_goals_condeded_by_teams,$total_points_final2);

  $content.='<table class="leaguetable">';
    $content.='<thead class="leaguetable-head">';
      $content.='<tr>';
        $content.='<th class="pos-head" data-toggle="tooltip" data-placement="top" title="Position">Pos</th>';
        $content.='<th class="team-head">Team</th>';
        $content.='<th class="played-head">GP</th>';
        $content.='<th class="own-head">W</th>';
        $content.='<th class="drawn-head">D</th>';
        $content.='<th class="lost-head">L</th>';
        $content.='<th class="gf-head">GF</th>';
        $content.='<th class="ga-head">GA</th>';
        $content.='<th class="gd-head">GD</th>';
        $content.='<th class="points-head">Pts</th>';
      $content.='</tr>';
    $content.='</thead>';
    $content.='<tbody class="table-body">';
    for($i=0;$i<sizeof($result['team_list']);$i++){
      $content.='<tr>';   
        $win_res;
        if($result['total_wins'][$result['team_list'][$i]]!=''){
          $win_res=$result['total_wins'][$result['team_list'][$i]];
        } else {
          $win_res=0;
        }

        $draw_res;
        if($result['team_drawn'][$result['team_list'][$i]]!=''){
          $draw_res=$result['team_drawn'][$result['team_list'][$i]];
        } else {
          $draw_res=0;
        }

        $loss_res;
        if($result['total_loses'][$result['team_list'][$i]]!=''){
          $loss_res=$result['total_loses'][$result['team_list'][$i]];
        } else {
          $loss_res=0;
        }

        $gf;
        if($result['total_goals_for'][$result['team_list'][$i]]!=''){
          $gf=$result['total_goals_for'][$result['team_list'][$i]];
        } else {
          $gf=0;
        }

        $ga;
        if($result['total_goals_against'][$result['team_list'][$i]]!=''){
          $ga=$result['total_goals_against'][$result['team_list'][$i]];
        } else {
          $ga=0;
        }
        $gd= ($gf-$ga);
        $tot_points;
        if($result['team_points'][$result['team_list'][$i]]!=''){
          $tot_points=$result['team_points'][$result['team_list'][$i]];
        } else {
          $tot_points=0;
        }

        $tot_points;
        if($result['team_points'][$result['team_list'][$i]]!=''){
          $tot_points=$result['team_points'][$result['team_list'][$i]];
        } else {
          $tot_points=0;
        }

        $content.='<td class="team-pos" >'.$result['team_postiion'][$result['team_list'][$i]].'</td>';
        $content.='<td class="team-logo-name"><img src="'.get_team_image_from_title($result['team_list'][$i]).'"  style="height:30px; width:30px;"/>'.$result['team_list'][$i].'</td>';
        $content.='<td class="team-played">'.$result['total_matches_played'][$result['team_list'][$i]].'</td>';
        $content.='<td class="team-win">'.$win_res.'</td>';
        $content.='<td class="team-draw">'.$draw_res.'</td>';
        $content.='<td class="team-loss">'.$loss_res.'</td>';
        $content.='<td class="team-gf">'.$gf.'</td>';
        $content.='<td class="team-ga">'.$ga.'</td>';
        $content.='<td class="team-gd">'.$gd.'</td>';
        $content.='<td class="team-points">'.$tot_points.'</td>';
      $content.='</tr>';
    }
    $content.='</tbody>';
  $content.='</table>';
  echo $content;
?>

It shows:

Notice: Undefined variable: content in C:\wamp\www\wordpress\wp-content\themes\testtheme\framework\league\table.php on line 98

Line 98 is:

$content.='<table class="leaguetable">';

Notice: Undefined index: FC Barcelona in C:\wamp\www\wordpress\wp-content\themes\testtheme\framework\league\table.php on line 131 Line 131 is:

$loss_res;
        if($result['total_loses'][$result['team_list'][$i]]!=''){
          $loss_res=$result['total_loses'][$result['team_list'][$i]];
        } else {
          $loss_res=0;
        }

Notice: Undefined index: Sevilla in C:\wamp\www\wordpress\wp-content\themes\testtheme\framework\league\table.php on line 124 Line 124 is:

$draw_res;
        if($result['team_drawn'][$result['team_list'][$i]]!=''){
          $draw_res=$result['team_drawn'][$result['team_list'][$i]];
        } else {
          $draw_res=0;
        }

Is there any solution? Any help would be appreciated.