JavaScript Dodaj ciąg na środek ciągu
function addStr(str, index, stringToAdd){
return str.substring(0, index) + stringToAdd + str.substring(index, str.length);
}
let str = "This is a string";
let stringToAdd = "modyfied ";
console.log(addStr(str, 10, stringToAdd)); //outPut : "This is a modified string"
CoderM