在javascript中将字节数组转换为字符串

Question

如何将字节数组转换为字符串？

我发现这些功能正好相反:

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;
}

但是如何让功能以其他方式运行？

谢谢.

邵

Answer 1

您需要将每个八位字节解析回数字,并使用该值来获取字符,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";

编辑:是的,您的当前内容string2Bin可以写得更快:

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

但是通过查看你链接的文档,我认为该setBytesParameter方法需要blob数组包含十进制数字,而不是一个字符串,所以你可以写这样的东西:

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

Answer 2

只需apply你的字节数组即可String.fromCharCode.例如

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

警告:适用于小于65535的数组.此处为MDN文档.

Answer 3

尝试使用新的文本编码API：

// create an array view of some valid bytes
let bytesView = new Uint8Array([104, 101, 108, 108, 111]);

console.log(bytesView);

// convert bytes to string
// encoding can be specfied, defaults to utf-8 which is ascii.
let str = new TextDecoder().decode(bytesView); 

console.log(str);

// convert string to bytes
// encoding can be specfied, defaults to utf-8 which is ascii.
let bytes2 = new TextEncoder().encode(str);

// look, they're the same!
console.log(bytes2);
console.log(bytesView);

Answer 4

这应该有效：

String.fromCharCode(...array);

或者

String.fromCodePoint(...array)

Answer 5

可以更简洁地编写string2Bin ,并且无需任何循环即可启动!

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

Answer 6

字符串到字节数组： "FooBar".split('').map(c => c.charCodeAt(0));

字节数组转字符串： [102, 111, 111, 98, 97, 114].map(c => String.fromCharCode(c)).join('');