Regular expression for two decimal places not working in JavaScript. Am I missing something?

Question

I am using a regular expression to validate input from a text field to only allow a whole number or a number with up to two decimal places (eg: 10, 10.4, 10.45, 100.45) ,however when I enter a number with 3 or more decimal places it will still validate it. Code shown below.

var loanAmount = document.getElementById("loan_amount");

var loanRE = /\d+(\.\d{1,2})?/;

if (!(loanRE.test(loanAmount.value))){
alert("Not a valid input for the loan amount");
return false;
}

Everything looks good to me. What am I missing?

Answer 1

Anchor your regex. loadRE = /^\\d+(\\.\\d{1,2})?$/

Otherwise it will just say "okay, there's some digits. It passes!"