将字节数组转换为javascript中的字符串。

How do I convert a byte array into a string?

如何将一个字节数组转换成字符串?

I have found these functions that do the reverse:

我发现这些函数的作用正好相反:

function string2Bin(s) {
    var b = new Array();
    var last = s.length;

    for (var i = 0; i < last; i++) {
        var d = s.charCodeAt(i);
        if (d < 128)
            b[i] = dec2Bin(d);
        else {
            var c = s.charAt(i);
            alert(c + ' is NOT an ASCII character');
            b[i] = -1;
        }
    }
    return b;
}

function dec2Bin(d) {
    var b = '';

    for (var i = 0; i < 8; i++) {
        b = (d%2) + b;
        d = Math.floor(d/2);
    }

    return b;
}

But how do I get the functions working the other way?

但是我怎样才能让函数反过来呢?

Thanks.

谢谢。

Shao

邵

5 个解决方案

#1

You need to parse each octet back to number, and use that value to get a character, something like this:

您需要将每个octet解析为数字，并使用该值来获得一个字符，如下所示:

function bin2String(array) {
  var result = "";
  for (var i = 0; i < array.length; i++) {
    result += String.fromCharCode(parseInt(array[i], 2));
  }
  return result;
}

bin2String(["01100110", "01101111", "01101111"]); // "foo"

// Using your string2Bin function to test:
bin2String(string2Bin("hello world")) === "hello world";

Edit: Yes, your current string2Bin can be written more shortly:

编辑:是的，您当前的string2Bin可以写得更短一些:

function string2Bin(str) {
  var result = [];
  for (var i = 0; i < str.length; i++) {
    result.push(str.charCodeAt(i).toString(2));
  }
  return result;
}

But by looking at the documentation you linked, I think that the setBytesParameter method expects that the blob array contains the decimal numbers, not a bit string, so you could write something like this:

但是通过查看您链接的文档，我认为setBytesParameter方法期望blob数组包含十进制数，而不是位串，所以您可以这样写:

function string2Bin(str) {
  var result = [];
  for (var i = 0; i < str.length; i++) {
    result.push(str.charCodeAt(i));
  }
  return result;
}

function bin2String(array) {
  return String.fromCharCode.apply(String, array);
}

string2Bin('foo'); // [102, 111, 111]
bin2String(string2Bin('foo')) === 'foo'; // true

#2

Simply apply your byte array to String.fromCharCode. For example

简单地将字节数组应用到String.fromCharCode中。例如

String.fromCharCode.apply(null, [102, 111, 111]) equals 'foo'.

apply(null， [102, 111, 111]) = 'foo'。

Caveat: works for arrays shorter than 65535. MDN docs here.

警告:对数组的作用小于65535。MDN文档。

#3

That string2Bin can be written even more succinctly, and without any loops, to boot!

这个string2Bin可以写得更简洁，而且没有任何循环，可以启动!

function string2Bin ( str ) {
    return str.split("").map( function( val ) { 
        return val.charCodeAt( 0 ); 
    } );
}

#4

I think this would be more efficient:

我认为这样更有效:

function toBinString (arr) {
    var uarr = new Uint8Array(arr.map(function(x){return parseInt(x,2)}));
    var strings = [], chunksize = 0xffff;
    // There is a maximum stack size. We cannot call String.fromCharCode with as many arguments as we want
    for (var i=0; i*chunksize < uarr.length; i++){
        strings.push(String.fromCharCode.apply(null, uarr.subarray(i*chunksize, (i+1)*chunksize)));
    }
    return strings.join('');
}

#5

Even if I'm a bit late, I thought it would be interesting for future users to share some one-liners implementations I did using ES6.

即使我有点晚了，我认为未来的用户也会有兴趣分享一些我使用ES6实现的单行实现。

One thing that I consider important depending on your environment or/and what you will do with with the data is to preserve the full byte value. For example, (5).toString(2) will give you 101, but the complete binary conversion is in reality 00000101, and that's why you might need to create a leftPad implementation to fill the string byte with leading zeros. But you may not need it at all, like other answers demonstrated.

根据您的环境或/您将如何处理数据，我认为重要的一点是保存完整的字节值。例如，(5). tostring(2)将给您101，但是完整的二进制转换实际上是00000101，这就是为什么您可能需要创建一个leftPad实现来填充带前导零的字符串字节。但你可能根本不需要它，就像其他的答案一样。

If you run the below code snippet, you'll see the first output being the conversion of the abc string to a byte array and right after that the re-transformation of said array to it's corresponding string.

如果您运行下面的代码片段，您将看到第一个输出是将abc字符串转换为字节数组，然后将该数组的重新转换为相应的字符串。

// For each byte in our array, retrieve the char code value of the binary value
const binArrayToString = array => array.map(byte => String.fromCharCode(parseInt(byte, 2))).join('')

// Basic left pad implementation to ensure string is on 8 bits
const leftPad = str => str.length < 8 ? (Array(8).join('0') + str).slice(-8) : str

// For each char of the string, get the int code and convert it to binary. Ensure 8 bits.
const stringToBinArray = str => str.split('').map(c => leftPad(c.charCodeAt().toString(2)))

const array = stringToBinArray('abc')

console.log(array)
console.log(binArrayToString(array))

#1