Replace special characters in a string with _ (underscore)

Question

I want to remove special characters from a string and replace them with the _ character.

For example:

string = \"img_realtime_tr~ading3$         


        

Answer 1

string = string.replace(/[&\/\\#,+()$~%.'":*?<>{}]/g,'_');

Alternatively, to change all characters except numbers and letters, try:

string = string.replace(/[^a-zA-Z0-9]/g,'_');

Answer 2

string = string.replace(/[\W_]/g, "_");