小编cra*_*aig的帖子

我有以下HTML

<form>
  <div class="answer1wrap">
    <select id="mySelect">
      <option value="void">Choose your answer</option>
      <option value="To measure time">To measure time</option>
      <option value="To measure distance">To measure distance</option>
      <option value="To measure volume">To measure volume</option>
    </select>
  </div>
</form>

<button class="btn btn-default" id="checkbtn" onclick="answers();" type="button"><span    class="glyphicon glyphicon-check"></span> Check answers</button>

我也有javascript

function answers()
{
  var selectedanswer=document.getElementById("mySelect").selectedIndex;

  if (document.getElementsByTagName("option")[selectedanswer].value=="To measure time");{
    alert("Thats correct"); 
  }
}

我希望当按下按钮时,它会检查是否选择了"测量时间"选项并仅在选中时提醒我.但是,无论选择哪个选项,它始终显示警报.

有任何想法吗？

有没有人知道使用paper.js清除画布的最佳方法我尝试了常规的画布清除方法,但它们似乎不适用于paper.js

HTML

<canvas id="myCanvas" style="background:url(images/graphpaper.jpg); background-repeat:no-repeat" height="400px" width="400px;"></canvas>

<button class="btn btn-default button" id="clearcanvas" onClick="clearcanvas();"     type="button">Clear</button>    

使用Javascript/Paperscript

<script type="text/paperscript" canvas="myCanvas">
// Create a Paper.js Path to draw a line into it:
tool.minDistance = 5;

var path;
var c=document.getElementById("myCanvas");
var ctx=c.getContext("2d");

function onMouseDown(event) {
// Create a new path and give it a stroke color:
path = new Path();
path.strokeColor = 'red';
path.strokeWidth= 3;
path.opacity="0.4";

// Add a segment to the path where
// you clicked:
path.add(event.point, event.point);
}

function onMouseDrag(event) { …

我有以下代码,我想凝聚成for循环,但不知道如何.我试着查看其他帖子,但卡住了.

共有15个数字,所以类似于(i = 1; i <= 15; i ++)

       if(checksquare1save=="true"){
            $("#checksquare1").toggleClass("checksquareON");
        }

        else{
            $("#checksquare1").removeClass("checksquareON");
        }

        if(checksquare2save=="true"){
            $("#checksquare2").toggleClass("checksquareON");
        }

        else{
            $("#checksquare2").removeClass("checksquareON");
        }

        if(checksquare3save=="true"){
            $("#checksquare3").toggleClass("checksquareON");
        }

        else{
            $("#checksquare3").removeClass("checksquareON");
        }

        if(checksquare4save=="true"){
            $("#checksquare4").toggleClass("checksquareON");
        }

        else{
            $("#checksquare4").removeClass("checksquareON");
        }

        if(checksquare5save=="true"){
            $("#checksquare5").toggleClass("checksquareON");
        }

        else{
            $("#checksquare5").removeClass("checksquareON");
        }

        if(checksquare6save=="true"){
            $("#checksquare6").toggleClass("checksquareON");
        }

        else{
            $("#checksquare6").removeClass("checksquareON");
        }

        if(checksquare7save=="true"){
            $("#checksquare7").toggleClass("checksquareON");
        }

        else{
            $("#checksquare7").removeClass("checksquareON");
        }

        if(checksquare8save=="true"){
            $("#checksquare8").toggleClass("checksquareON");
        }

        else{
            $("#checksquare8").removeClass("checksquareON");
        }

        if(checksquare9save=="true"){
            $("#checksquare9").toggleClass("checksquareON");
        }

        else{
            $("#checksquare9").removeClass("checksquareON");
        }

        if(checksquare10save=="true"){
            $("#checksquare10").toggleClass("checksquareON");
        }

        else{
            $("#checksquare10").removeClass("checksquareON");
        }

        if(checksquare11save=="true"){
            $("#checksquare11").toggleClass("checksquareON");
        }

        else{
            $("#checksquare11").removeClass("checksquareON");
        }

        if(checksquare12save=="true"){
            $("#checksquare12").toggleClass("checksquareON");
        }

        else{
            $("#checksquare12").removeClass("checksquareON"); …

我有以下javascript.

有没有让这更简单.看起来很重？

它基本上取12个输入的值,并根据这些值更改数组

   function updatechart (){
    var inputnoinsulation1 = document.getElementById("noinsulation1").value
    var inputnoinsulation2 = document.getElementById("noinsulation2").value
    var inputnoinsulation3 = document.getElementById("noinsulation3").value
    var inputnoinsulation4 = document.getElementById("noinsulation4").value
    var inputnoinsulation5 = document.getElementById("noinsulation5").value
    var inputnoinsulation6 = document.getElementById("noinsulation6").value
    var inputnoinsulation7 = document.getElementById("noinsulation7").value
    var inputnoinsulation8 = document.getElementById("noinsulation8").value
    var inputnoinsulation9 = document.getElementById("noinsulation9").value
    var inputnoinsulation10 = document.getElementById("noinsulation10").value
    var inputnoinsulation11 = document.getElementById("noinsulation11").value
    var inputnoinsulation12 = document.getElementById("noinsulation12").value

    chart1data[0].NoInsulation = (parseInt(inputnoinsulation1));
    chart1data[1].NoInsulation = (parseInt(inputnoinsulation2));
    chart1data[2].NoInsulation = (parseInt(inputnoinsulation3));
    chart1data[3].NoInsulation = (parseInt(inputnoinsulation4));
    chart1data[4].NoInsulation = (parseInt(inputnoinsulation5));
    chart1data[5].NoInsulation = (parseInt(inputnoinsulation6));
    chart1data[6].NoInsulation = (parseInt(inputnoinsulation7));
    chart1data[7].NoInsulation = (parseInt(inputnoinsulation8));
    chart1data[8].NoInsulation = …

我有以下数组

  DataArray = [{
    "Year": "Year 7",
        "test1": 28,
        "test2": 19,
         "test3": 22,
         "average": ''

}, {
    "Year": "Year 8",
        "test1": 15,
        "test2": 28,
        "test3": 22,
        "average": ''           

}, {
    "Year": "Year 9",
        "test1": 25,
        "test2": 24,
         "test3": 22,
        "average": ''
 }, {
    "Year": "Year 10",
        "test1": 26,
        "test2": 19,
         "test3": 22,
        "average": ''            
}, {
    "Year": "Year 11",
        "test1": 48,
        "test2": 52,
         "test3": 22,
        "average": ''            
}];

我怎样才能使'average'的值是每个对象中test 1,test 2和test 3的平均值？