contains 函数在运行相同代码时​，为什么返回了不同的​逻辑数组？

a=[    "水果店"    "武汉水果店"        "宜昌水果店"        "襄阳水果店"    "荆州水果店"  
    "饭店"     "武汉饭店"          "宜昌饭店"          "襄阳饭店"      "荆州饭店"     ];

store_name ={'宜昌水果店','武汉水果店'};
T=contains(a,store_name{1});
T

T = 2x5 logical array
   0   0   0   0   0
   0   0   0   0   0

store_name ={'宜昌水果店','武汉水果店'};
T=contains(a,store_name{1});
T

T = 2x5 logical array
   0   0   1   0   0
   0   0   0   0   0

Answer 1

[Voss]

There is a hidden character at the beginning of the first store_name{1}

store_name ={'宜昌水果店','武汉水果店'};

+store_name{1} % character codes

ans = 1x6

65279 23452 26124 27700 26524 24215

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which is not in the second store_name{1}

store_name ={'宜昌水果店','武汉水果店'};

+store_name{1} % character codes

ans = 1x5

23452 26124 27700 26524 24215

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There are various ways to remove that extra character, e.g., using strrep:

store_name ={'宜昌水果店','武汉水果店'}; % 1st one again

+store_name{1} % character codes

ans = 1x6

65279 23452 26124 27700 26524 24215

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store_name{1} = strrep(store_name{1},char(65279),'');

+store_name{1} % character codes

ans = 1x5

23452 26124 27700 26524 24215

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Now they are the same and produce the same result when checking against a.

a=[    "水果店"    "武汉水果店"        "宜昌水果店"        "襄阳水果店"    "荆州水果店"  
    "饭店"     "武汉饭店"          "宜昌饭店"          "襄阳饭店"      "荆州饭店"     ];

store_name ={'宜昌水果店','武汉水果店'};
store_name{1} = strrep(store_name{1},char(65279),'');

T = contains(a,store_name{1})

T = 2x5 logical array
   0   0   1   0   0
   0   0   0   0   0

store_name ={'宜昌水果店','武汉水果店'};
T = contains(a,store_name{1})

T = 2x5 logical array
   0   0   1   0   0
   0   0   0   0   0

https://www.mathworks.com/help/matlab/ref/strrep.html

https://www.fileformat.info/info/unicode/char/feff/index.htm

https://en.wikipedia.org/wiki/Byte_order_mark