> ### Describe the Issue > Example JavaScript Calculator accepts invalid input. > > ### Affected Page > https://javascript-calculator.freecodecamp.rocks/ > > ### Your code > ``` > *2= > ``` > > ``` > /2= > ``` > > ``` > /2/2= > ``` > > ### Expected behavior > It should ignore invalid input. > > ### Screenshots >    > > ### System > Device: Laptop OS: Windows 18.04.5 Browser: Chrome > > ### Additional context > https://www.freecodecamp.org/learn/front-end-development-libraries/front-end-development-libraries-projects/build-a-javascript-calculator