請參閱評論后的第2行。這個問題在代碼注釋中有提到。//valid input to be taken by uservar validanswerone = ["yes" , "YES", "Yes"];//here i want to take multiple form of input the user might type but my efforts are going effort less.var validanswertwo = "no";//only this is working.//conditionsif (userage === validanswerone){  console.log("\n\nPlease put your credit card details in the next page" + ", you will be redirected soon!");}else if(userage === validanswertwo){  console.log("\n\nWe are sorry!");  console.log("\n\nPlease try back in" + "  *days remaining to be become 18+ will be added in the coming update still not understood the formula to implicate it*");}else{  console.log("\n\nInvalid input!")}