In this article, the task is to get the nth occurrence of a substring in a string with the help of JavaScript. We have many methods to do this some of which are described below:
Approaches to get the nth occurrence of a string:
Approach 1: Using split() and join() methods
- First, split the string into sub-strings using the split() method by passing the index also.
- Again join the substrings on the passed substring using join() method.
- Returns the index of the nth occurrence of the string.
Example: In this example, the split() and join() methods are used to get the index of a substring.
Javascript
// Input stringlet string = "Geeks gfg Geeks Geek Geeks gfg";// String to searchlet searchString = "Geeks";// occurrence numberlet occurrence = 3;console.log( occurrence + "rd occurrence of a '" + searchString + "' in " + string + "'.");// Function to get index of occurrencefunction getPos(str, subStr, i) { return str.split(subStr, i).join(subStr).length;}function GFG_Fun() { console.log(getPos( string, searchString, occurrence ));}GFG_Fun(); |
Output
3rd occurrence of a 'Geeks' in Geeks gfg Geeks Geek Geeks gfg'. 21
Approach 2: Using indexOf() method
Go through each substring one by one and return the index of the last substring. This approach uses the indexOf() method to return the index of the nth occurrence of the string.
Example: This example uses the indexOf() method to find the index of a substring.
Javascript
// Input stringlet string = "Geeks gfg Geeks Geek Geeks gfg";// String to searchlet searchString = "Geeks";// occurrence numberlet occurrence = 3;console.log( occurrence + "rd occurrence of a '" + searchString + "' in " + string + "'.");// Function to get index of occurrencefunction getIndex(str, substr, ind) { let Len = str.length, i = -1; while (ind-- && i++ < Len) { i = str.indexOf(substr, i); if (i < 0) break; } return i;}function GFG_Fun() { console.log(getIndex(string, searchString, occurrence));}GFG_Fun(); |
Output
3rd occurrence of a 'Geeks' in Geeks gfg Geeks Geek Geeks gfg'. 21
