中文字符串的编解码，有人知道吗？

let decimal =16; 
let str = "万剑归宗 1234 abcd"; 
console.log('编码前:' + str); 
  
function strToDecimal(str: string, decimal: number): string { 
  return Array.from(str).map(char => char.charCodeAt(0).toString(decimal)).join(' ') 
} 
  
let total2str =  strToDecimal(str, decimal); 
console.log("编码后:" + total2str) 
  
function decimalToStr(str: string, decimal: number): string { 
  return str.split(' ').map(unit => String.fromCharCode(parseInt(unit, decimal))).join('') 
} 
  
console.log("解码后:" + decimalToStr(total2str,decimal))

let str = "万剑归宗 1234 abcd"; 
console.log('编码前:' + str); 
  
let output = new util.TextEncoder("utf-8").encodeInto(str) 
console.log("编码后:" + output.toString()) 
  
let decoder = util.TextDecoder.create("utf-8"); 
let decodeStr:string = decoder.decodeWithStream(new Uint8Array(output)) 
console.log("解码后:" + decodeStr) 
  
function stringEncode(str: string): string { 
  if (str.length <=0) { 
    return '' 
  } 
  return new util.TextEncoder("utf-8").encodeInto(str).toString() 
} 
  
function stringDecode(str: string): string { 
  if (str.length <=0) { 
    return '' 
  } 
  
  let arry:Array<number> = [] 
  str.split(',').map((char)=>{ arry.push(parseInt(char))}) 
  return util.TextDecoder.create("utf-8").decodeWithStream(new Uint8Array(arry)) 
}