什么是代理对？ [英] What is a surrogate pair?

问题描述

  validator.isLength = function（str，min，max ）
 //在字符串中匹配代理对，或者声明一个空数组（如果没有在字符串中找到）
 var surrogatePairs = str.match（/ [\\\�-\\\�] [\\\�-\ uDFFF] / g）|| []; 
 //从主字符串长度减去代理对字符串长度
 var len = str.length  -  surrogatePairs.length; 
 //现在将字符串长度与最小和最大值进行比较...还确保定义max（换句话说，max param对于函数是可选的）
 return len> = min&& （typeof max ==='undefined'|| len <= max）; 
}; 
  

据了解，上述代码检查字符串的长度，但不使用代理成对考虑。所以：

1. 我对代码的理解是否正确？




2. 什么是代理对？

我迄今为止只知道这与编码有关。 / p>

解决方案

你是否尝试只是google？

最好的描述是 http://unicodebook.readthedocs.io/unicode_encodings.html#surrogates

在UTF-16中，一些字符存储在8位，其他字符存储在16位。

代理对是一个字符代表16位。
某些字符代码被保留为成对的第一个。

I came across this code in a javascript open source project.

validator.isLength = function (str, min, max) 
    // match surrogate pairs in string or declare an empty array if none found in string
    var surrogatePairs = str.match(/[\uD800-\uDBFF][\uDC00-\uDFFF]/g) || [];
    // subtract the surrogate pairs string length from main string length
    var len = str.length - surrogatePairs.length;
    // now compare string length with min and max ... also make sure max is defined(in other words, max param is optional for function)
    return len >= min && (typeof max === 'undefined' || len <= max);
};

As far as I understand, the above code is checking the length of the string but not taking the surrogate pairs into account. So:

1. Is my understanding of the code correct?

2. What are surrogate pairs?

I have thus far only figured out that this is related to encoding.

解决方案

Did you try to just google it?

The best description is http://unicodebook.readthedocs.io/unicode_encodings.html#surrogates

In UTF-16 some characters are stored in 8 bits and others in 16 bits.

Surrogate pair is a character representation that take 16 bits. Some character codes is reserved to be the first one in such pairs.

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