You should use the string replace function, with a single regex. Assuming by special characters, you mean anything that's not letter, here is a solution:

const str = "abc's test#s";
console.log(str.replace(/[^a-zA-Z ]/g, ""));

Use this for the regex instead:

 /[^\w.]|_/g

It reads any character that is not either alpha-numerical (which includes underbars) or dot, or that is an under bar.

update
But this is perhaps little more readable:

/[^0-9a-zA-Z.]/g

Use the global flag:

var name = name.replace(/[^a-zA-Z ]/g, "");
                                    ^

If you don't want to remove numbers, add it to the class:

var name = name.replace(/[^a-zA-Z0-9 ]/g, "");