jquery - 如何在 jquery 上运行 if-else 语句？

Question

我有下面的代码。现在我想对其运行 if-else 语句，但它不起作用。有什么想法吗？

var num1 = $('#id1').val(); 
var num2 = $('#id2').val();

var newVal = (num1+2)*(num2/4);
var nextVal =(num1+4)*(num2/2);
var newArr = new Array();
newArr.push(newVal);
newArr.push(nextVal);

newArr.sort();

if(newArr.get(0)==newVal)
$("body").html("<p>works fine!</p>");
else $("body").html("<p>works awfully!</p>");

Answer 1

只需使用newArr[0]而不是newArr.get(0)

Answer 2

val将返回一个字符串，因此您可能必须转换为数字。您可以使用一元加号运算符：

var num1 = +$('#id1').val(); // Now you get 5 instead of "5" 
var num2 = +$('#id2').val();

//The problem shows up here when you are doing string concatenation instead of addition in the first set of parenthesis
var newVal = (num1+2)*(num2/4);

if(newArr[0]==newVal) // .get is for jQuery collections, just use brackets on an array

Answer 3

您在这一行用大写 V 声明了“Var”：

Var newVal = (num1+2)*(num2/4);

此外，使用 [index] 访问数组的元素，而不是 .get(index)

这是编辑后的代码：

  var num1 = 50;   
  var num2 = 100;

  var newVal = parseInt((num1+2)*(num2/4));
  var nextVal =parseInt((num1+4)*(num2/2));
  var newArr = new Array();
  newArr.push(newVal);
  newArr.push(nextVal);

  newArr = newArr.sort(function(a,b){return a - b});

  if(newArr[0]==newVal)
    $("body").html("<p>works fine!</p>");
  else
    $("body").html("<p>works awfully!</p>");​ 

Answer 4

试试这个

var num1 = 50;   
  var num2 = 100;

  var newVal = (num1+2)*(num2/4);
  var nextVal =(num1+4)*(num2/2);
  var newArr = new Array();
  newArr.push(newVal);
  newArr.push(nextVal);

  newArr.sort();

  if(newArr[0]==newVal)
    $("body").html("<p>works fine!</p>");
  else
    $("body").html("<p>works awfully!</p>");