PHP fgetcsv() - find number of columns

问题

I'm trying to determine how many columns a csv file has.

Here's my script, which is only utilizing the first column, but I'm running slightly blind. I want to place a variable that limits the column count. (since I may make a mistake and add a column, or even miss a column)

<?php
$allowedColNum=5;
$batchcount=0;
$file = fopen($file_name, "r"); 
while ($line = fgetcsv($file)){
 /* I want to stop the loop if the $allowedColNum is not correct */                 
  $col = $line[0]; 
  echo $batchcount++.". ".$col."\n";
}

fclose($file);
?>

I'm sure it's one of those easy easy things that I'm not getting.

回答1:

If I understand, you simply need count($line), because fgetcsv() has returned an array representing one row from the CSV file. The array's count() is therefore the number of source columns.

while ($line = fgetcsv($file)){

  // count($line) is the number of columns
  $numcols = count($line);

  // Bail out of the loop if columns are incorrect
  if ($numcols != $allowedColNum) {
     break;
  }
  $col = $line[0]; 
  echo $batchcount++.". ".$col."\n";
}

回答2:

Not tested, but should work!

$allowedColNum=5;
$batchcount=0;
$file = fopen($file_name, "r"); 
$totCols=0;
while ($line = fgetcsv($file))
if(count($line) > $totCols) $totCols = count($line);
fseek($file, 0);
while ($line = fgetcsv($file))
{
  //....
}
fclose($file);

edit: tested, working do fseek(0) instead of save the values in an array: will be a lot faster

回答3:

Michael Berkowski answer work fine for me, but in my case, i also had to specify the csv separator in the fgetcsv() function call. It's Comma "," by default, i change it to semicolon ";". Like this:

while ($line = fgetcsv($file, 0, ';')){

来源：https://stackoverflow.com/questions/7678266/php-fgetcsv-find-number-of-columns

标签

php

fgetcsv