[Vuejs]-Error on saving to local storage for Vue.js

I think your problem is that you are only initializing this.result if localStorage.result has a value. If localStorage.result doesn’t have a value the first time you call saveList this.result is still undefined. Try setting a default value or skip trying to save if the value is still undefined. I am also not sure of the relationship between this.List and this.result, since List seems to be a list of results?