string-splice

Useage:

splice(str, index, count, add)

Example

var splice = require('string-splice') ;

var exampleString = 'abcdefg'

splice(exampleString, 1, 2, 'ZZZ');
//'aZZZdefg'

Attributions:

Taken from the answer to this stack overflow question: http://stackoverflow.com/questions/20817618/is-there-a-splice-method-for-strings