douhu4091 2018-08-06 09:50
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为什么str_ireplace会出现意外行为并仅针对一个针复制数据?

I have wrote a small piece of code for converting some food ingredients from the US format to international format.

To achieve this, I am using str_ireplace. This is working for everything except the needle "Blue 1". The expected output is Brilliant blue (E133) * but the actual output is Brilliant blue (E133) * (E133) *

Why is str_ireplace adding another (E133) * to the end of the string?

$ingredients = "Blue 1";

$find_colors = array(
    'Allura red',
    'Food Red 17',
    'C.I. 16035',
    'Red 40',
    'Carmoisine',
    'Azorubine',
    'Food Red 3',
    'Azorubin S',
    'Brilliantcarmoisin O',
    'Red 14',
    'C.I. 14720',
    'Ponceau 4R',
    'Cochineal Red A',
    'C.I. 16255',
    'Acid Red 18',
    'Brilliant Scarlet 3R',
    'Brilliant Scarlet 4R',
    'New Coccine',
    'SX Purple',
    'Quinoline yellow',
    'C.I. 47005',
    'Yellow 13',
    'Acid Yellow 3',
    'Sunset yellow',
    'Yellow 6',
    'C.I. 15985',
    'Tartrazine',
    'Yellow 5',
    'Blue 1',
    'Brilliant Blue',
    'Acid Blue 9',
    'Blue 2',
    'Yellow #5',
    'C.I. 19140',
    'red 3'
);
$replace_colors = array(
    'Allura red (E129) *',
    'Allura red (E129) *',
    'Allura red (E129) *',
    'Allura red (E129) *',
    'Carmoisine (E122) *',
    'Carmoisine (E122) *',
    'Carmoisine (E122) *',
    'Carmoisine (E122) *',
    'Carmoisine (E122) *',
    'Carmoisine (E122) *',
    'Carmoisine (E122) *',
    'Ponceau 4R (E124) *',
    'Ponceau 4R (E124) *',
    'Ponceau 4R (E124) *',
    'Ponceau 4R (E124) *',
    'Ponceau 4R (E124) *',
    'Ponceau 4R (E124) *',
    'Ponceau 4R (E124) *',
    'Ponceau 4R (E124) *',
    'Quinoline yellow (E104) *',
    'Quinoline yellow (E104) *',
    'Quinoline yellow (E104) *',
    'Quinoline yellow (E104) *',
    'Sunset yellow (E110) *',
    'Sunset yellow (E110) *',
    'Sunset yellow (E110) *',
    'Tartrazine (E102) *',
    'Tartrazine (E102) *',
    'Brilliant blue (E133) *',
    'Brilliant blue (E133) *',
    'Brilliant blue (E133) *',
    'Indigo carmine (E132) *',
    'Tartrazine (E102) *',
    'Tartrazine (E102) *',
    'Allura red (E129) *'
);

$ingredients = str_ireplace($find_colors, $replace_colors, $ingredients);

echo $ingredients;

This behaviour does not seem to occur with any other needle. Additionally, if I remove all other needles and haystack, the issue does not occur.

Why is str_ireplace repeating these characters?

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1条回答 默认 最新

  • doule0941 2018-08-06 10:14
    关注

    It's because you also have Brilliant Blue as an option, which if finds once you replace blue 1 with Brilliant blue (E133) *.

    This simplest solution is to always look for the longest replacement string first, so switch the options...

    'Brilliant Blue',
    'Blue 1',
    
    本回答被题主选为最佳回答 , 对您是否有帮助呢?
    评论

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