我在構建函數時遇到問題。它應該檢測用戶放入框中的內容是否為整數，并打印正確的評論。問題出現在函數的第二級中，指令“if”應該再次檢查圖1是否是一個數字（它不會打印任何東西），但是“else if”被完美地讀取，“else”也是如此。我的功能有什么問題？請幫忙。function show() {  //Variable contains the value of field1 from input html which has been read thanks to onclick  var figure1 = document.getElementById("field1").value;   //Variable contains the value of field2 from input html which has been read thanks to onclick  var figure2 = document.getElementById("field2").value;   //empty until the instruction write in something  let sign = "";  //STEP 1  //loop working until the value of i reach the value of figure2  for (i = figure1; i <= figure2; i++)   {    if (Number(figure1) && Number(figure2)) {      //if both figure1 and figure2 are numbers, print the sign as follows - what sign contains from previous iteration + i + ", "      sign = sign + i + ", ";           } else {          if (Number(figure1)) {        //If statements from "if" level above haven't been fulfilled, print "Please, type integer in right-hand box";        sign = "Prosz? wpisa? liczb? w prawym polu";               } else if (Number(figure2)) {        //If statements from "if" level above haven't been fulfilled, print "Please, type integer in left-hand box";        sign = "Prosz? wpisa? liczb? w lewym polu";               } else {        sign = "Prosz? wpisa? warto?ci liczbowe w obu polach";        // If statements from "if"        // level above haven 't been fulfilled, print "Please, type integer in both boxes";      }    }  }  //podmienia warto?? diva o id result na warto?? zmiennej sign.  document.getElementById("result").innerHTML = sign; }