Replace nth occurrence of string

Question

For example:

\'abcjkjokabckjk\'.replace(\'/(abc)/g\',...)

If I want to replace a specify position \'abc\', what I can do?

Like this

Answer 1

This can be done without RegEx.

String methods String#indexOf, String#lastIndexOf can be used with String#substring

var string = 'abcde|abcde|abcde|abcde',
  needle = 'abc',
  firstIndex = string.indexOf(needle),
  lastIndex = string.lastIndexOf(needle);

// ----------------------------------------------------------------
// Remove first occurence
var first = string.substring(0, firstIndex) + '***' + string.substring(firstIndex + needle.length);
document.getElementById('first').innerHTML = first;

// ----------------------------------------------------------------
// Remove last occurence
var last = string.substring(0, lastIndex) + '***' + string.substring(lastIndex + needle.length);
document.getElementById('last').innerHTML = last;

// ----------------------------------------------------------------
// Remove nth occurence
// For Demo: Remove 2nd occurence
var counter = 2, // zero-based index
  nThIndex = 0;

if (counter > 0) {
  while (counter--) {
    // Get the index of the next occurence
    nThIndex = string.indexOf(needle, nThIndex + needle.length);
  }
  
  // Here `nThIndex` will be the index of the nth occurence
}

var second = string.substring(0, nThIndex) + '***' + string.substring(nThIndex + needle.length);
document.getElementById('second').innerHTML = second;

table tr td:nth-child(2) {
  color: green;
}
td {
  padding: 15px;
}

  

    
After replacing first occurence:
    

  
  

    
After replacing last occurence:
    

  
  

    
After replacing 2ndzero-based index occurence: