javascript订单小费打赏在线计算器工具

使用方法

//Calculate Tip
function calculateTip() {
  var billAmt = document.getElementById("billamt").value;
  var serviceQual = document.getElementById("serviceQual").value;
  var numOfPeople = document.getElementById("peopleamt").value;

  //validate input
  if (billAmt === "" || serviceQual == 0) {
    alert("Please enter values");
    return;
  }
  //Check to see if this input is empty or less than or equal to 1
  if (numOfPeople === "" || numOfPeople <= 1) { numOfPeople = 1; document.getElementById("each").style.display = "none"; } else { document.getElementById("each").style.display = "block"; } //Calculate tip var total = (billAmt * serviceQual) / numOfPeople; //round to two decimal places total = Math.round(total * 100) / 100; //next line allows us to always have two digits after decimal point total = total.toFixed(2); //Display the tip document.getElementById("totalTip").style.display = "block"; document.getElementById("tip").innerHTML = total; } //Hide the tip amount on load document.getElementById("totalTip").style.display = "none"; document.getElementById("each").style.display = "none"; //click to call function document.getElementById("calculate").onclick = function() { calculateTip(); };