var.replace is not a function

Question

I\'m using the below code to try to trim the string in Javascript but am getting the error mentioned in the title:

function trim(str) {
    return str.replac         


        

Answer 1

probable issues:

• variable is NUMBER (instead of string);
  num=35; num.replace(3,'three'); =====> ERROR
num=35; num.toString().replace(3,'three'); =====> CORRECT !!!!!!
num='35'; num.replace(3,'three'); =====> CORRECT !!!!!!
• variable is object (instead of string);
• variable is not defined;