Question

是否可以制作类似数组的函数？这样，以下功能可以变得简单并且易于编辑。

function q1() {
  var theForm = document.forms["contact-form"];
  var quantity = theForm.elements["q1"];
  var howmany = 0;
  if (quantity.value != "") {
    howmany = parseInt(quantity.value);
  }
  return howmany;
}

function q2() {
  var theForm = document.forms["contact-form"];
  var quantity = theForm.elements["q2"];
  var howmany = 0;
  if (quantity.value != "") {
    howmany = parseInt(quantity.value);
  }
  return howmany;
}

function q3() {
  var theForm = document.forms["contact-form"];
  var quantity = theForm.elements["q3"];
  var howmany = 0;
  if (quantity.value != "") {
    howmany = parseInt(quantity.value);
  }
  return howmany;
}

现在我改变了这样 GetQuantity（）用于从Qty字段中获取值。例如q_A01 .. GetPrice（）用于获取只读值Price字段。例如p_A01 .. calculateTotal（）用于计算totalprice并返回字段ID“Total”。

function GetQuantity(e) {
var theForm = document.forms["contact-form"];
var quantity = theForm.elements[e];
var howmany =0;
if(quantity.value!=0) {
howmany = parseInt(quantity.value); }
return howmany;
}
function GetPrice(e) {
    var theForm = document.forms["contact-form"];
    var price = theForm.elements[e];
    var howmany =0;
    if(price.value!=0) {
    howmany = parseInt(price.value); }
    return howmany;
    }

function calculateTotal()
{
    var cakePrice =
GetPrice(p_A01)*GetQuantity(q_A01)+
GetPrice(p_A02)*GetQuantity(q_A02)+
GetPrice(p_A03)*GetQuantity(q_A03)+
GetPrice(p_F11)*GetQuantity(q_F11);

  var Totalordered = document.getElementById ("Total");
         Totalordered.value = cakePrice;


}

Answer 1

不确定为什么没有一个答案暗示明显 - 将公共代码保留在函数体中，并使可变代码成为函数参数：

function q(e) {
  var theForm = document.forms["contact-form"];
  var quantity = theForm.elements[e];
  var howmany = 0;
  if (quantity.value != "") {
    howmany = parseInt(quantity.value);
  }
  return howmany;
}

或更短版本，与原始版本几乎相同：

function q(e) {
  var quantity = document.forms["contact-form"].elements[e];
  return (quantity && quantity.value) || 0;
}

Answer 2

你所有的功能都做同样的事情。只需将不同的数据传递到一个函数中：

<xs:minInclusivevalue="0"/>
<xs:maxInclusivevalue="20"/>
<xs:pattern value="([1-9]?[0-9])|([1-9]?[0-9].5)"/>

但有趣的是，一个变化（数量）的东西是你的功能实际上并没有做任何事情。

这是任何编程语言中函数的基本前提，也是DRY一般最佳实践原则的基础（不要重复自己）。由于您的所有功能都做同样的事情，只需采取不同的（数量）并将其与功能分开。现在，您没有5个存储和维护功能。

Answer 3

在这里，您可以为所有输入使用一个函数，只需在其中传递输入ID或名称，并获取该元素的值。

＆＃13;

private int id, id100px;
private String rollNumber;
private String mobile_number, email_id, nick_name, hobbies, dob, name;
private Testimony[] testimony;


    public People(String name, int id, String mobile_number, String email_id,  Testimony ... testimony) {
        this.name = name;
        this.id = id;
        this.mobile_number = mobile_number;
        this.email_id = email_id;
        this.testimony = testimony;
    }

    public Testimony[] getTestimony() {
        return testimony;
    }

    public String getEmail_id() {
        return email_id;
    }

    public int getId() {
        return id;
    }

    public String getMobile_number() {
        return mobile_number;
    }

    public String getName() {
        return name;
    }

}

＆＃13;

Answer 4

Hi check the following code as you updated   
  function GetQuantity(e) {
        var theForm = document.forms["contact-form"];
        var quantity = theForm.elements[e];
        var howmany =0;
        if(quantity.value!=0) {
        howmany = parseInt(quantity.value); }
        return howmany;
    }
    function GetPrice(e) {
        var theForm = document.forms["contact-form"];
        var price = theForm.elements[e];
        var howmany =0;
        if(price.value!=0) {
        howmany = parseInt(price.value); }
        return howmany;
        }

    function calculateTotal()
    {
        var cakePrice =
    GetPrice('p_A01')*GetQuantity('q_A01')+
    GetPrice('p_A02')*GetQuantity('q_A02')+
    GetPrice('p_A03')*GetQuantity('q_A03')+
    GetPrice('p_F11')*GetQuantity('q_F11');

      var Totalordered = document.getElementById ("Total");
             Totalordered.value = cakePrice;


    }
            calculateTotal();

制作一个javascript的数组函数

4 个答案: