[removed] Async/await in .replace

Question

I am using the async/await function the following way

async function(){
  let output = await string.replace(regex, async (match)=>{
    let data = await someF         


        

Answer 1

This replaceAsync function iterates through all occurrences of a substring in a string by a regex and enable you to use an asynchronous exampleReplaceFunc function to replace them one by one (e.g. based on the match group as parameter).

const replaceAsync = async (str, regex, getNewSubstr) => {
  while (str.match(regex)) {
    const result = str.match(regex);
    const { index } = result;
    const [match, group1] = result;
    const newSubstr = await getNewSubstr(match, group1);
    str = `${str.substr(0, index)}${newSubstr}${str.substr(
      index + match.length
    )}`;
  }
  return str;
};


const exampleReplaceFunc = async (match, group) => {
  return new Promise(resolve => {
    setTimeout(() => {
      console.log(`'${match}' has been changed to 'new${group}'`);
      resolve(`new${group}`);
    }, 1500);
  });
};

const app = async () => {
  const str = "aaaaold1 aaold2aa aold3aa old4 aold5aa";
  console.log('original string:', str) 
  const newStr = await replaceAsync(str, /old([\d])/, exampleReplaceFunc);
  console.log('new string:', newStr);
};

app();