dpruwm6206 2014-12-11 10:24
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在php中添加字符串和数字(​​FAULT !!)

I'm having little trouble with this code that reads ordernumbers from txt file, then adds 1 to that number. However PHP does not add these numbers together regardless of automatic type-casting...

    $handle1 = fopen("ordernumbers.txt", "r");
    $numberoforders = fgets($handle1);
    $numberoforders = trim($numberoforders);
    $orderid=$numberoforders+1;
    echo $orderid;

When echoing $numberoforders, it returns number 5 (type is string)

When echoing $orderid, it returns 1, while it should give 6.

I can not see any problem here, and it still does not work. I tried also to change that variable type from string to int, and then add these numbers together, but same result (1).

edit:here's the contents of the txt file: http://imgur.com/bzjOuOJ

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  • doucheng1063 2014-12-11 11:07
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    Because $numberoforders is converted into integer and its value is 0, so 0 + 1 =1 that's the output you are getting . If you want the string's characters number add to the integer value, you need to count the string's length first.

    You can get your result like so

      $handle1 = fopen("ordernumbers.txt", "r");
      $numberoforders = fgets($handle1);
      $numberoforders = trim($numberoforders);
      $numberoforders  = strlen($numberoforders);
      $orderid=$numberoforders+1;
      echo $orderid;
    
    评论

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