It was coming because instead of return statement I was printing the output using console.log(). It has nothing to do with sorting cause I was not using any sort array method. The code had only 30 lines of code and it was pointing error at lines 63 and 88, How is it even possible.

Anyone know why I am seeing this.

TypeError: Cannot read property 'sort' of undefined
at testAnagrams
at /home/codewarrior/index.js:63:13
at /home/codewarrior/index.js:88:5
at Object.handleError

STDERR
/runner/frameworks/javascript/cw-2.js:237
throw ex;
^

TypeError: Cannot read property 'sort' of undefined
at testAnagrams (/home/codewarrior/index.js:56:18)
at /home/codewarrior/index.js:63:13
at /home/codewarrior/index.js:88:5
at Object.handleError (/runner/frameworks/javascript/cw-2.js:233:11)
at Object. (/home/codewarrior/index.js:3:6)
at Module._compile (module.js:652:30)
at Object.Module._extensions..js (module.js:663:10)
at Module.load (module.js:565:32)
at tryModuleLoad (module.js:505:12)
at Function.Module._load (module.js:497:3)
at Module.require (module.js:596:17)
at require (internal/module.js:11:18)
at [eval]:1:1
at ContextifyScript.Script.runInThisContext (vm.js:50:33)
at Object.runInThisContext (vm.js:139:38)
at Object. ([eval]-wrapper:6:22)