如何從我的字符串中刪除最後一個逗號，並用Javascript中的句號替換它？

Question

CSS：

.dynamicDiv { 
    width:200px; 
    border:solid 1px #c0c0c0; 
    background-color:#e1e1e1; 
    font-size:11px; 
    font-family:verdana; 
    color:#000; 
    padding:5px; 
    } 

的Javascript：

//create array 
    var myNames=new Array(); 
    //var nameString=document.getElementById(myNames.toString()) 

    function addToDiv() 
    { 
     //1) add name to div 
     document.getElementById('divName').innerHTML = document.getElementById('divName').innerHTML + document.getElementById('enter_name').value + "<br>"; 
     //2) now add the value to an array 
     myNames.push(document.getElementById('enter_name').value); 
     //strHTML = document.getElementById('divName').innerHTML + document.getElementById('enter_name').value + "<br>"; 
     //document.getElementById('divName').innerHTML = strHTML; 
    } 

    function displayMessage() 
    { 
     //debugger; 
     var strMessage = "Welcome to this page "; 

     //loop throught the array and add the element values to strMessage 
     for(i=0;i<=myNames.length-1;i++) 
     { 
      strMessage = strMessage + myNames[i] + ", " 
     } 

     //remove trainling comma 
     //strMessage = strMessage 

     alert(strMessage); 
    } 

    function displayMessagebye() 
    { 
     //debugger; 
     var strMessage = "Thank you for coming to this page "; 

     //loop throught the array and add the element values to strMessage 
     for(i=0;i<=myNames.length-1;i++) 
     { 
      strMessage = strMessage + myNames[i] + ", " 
     } 

     //remove trainling comma 
     //strMessage = strMes 
     //strMessage = strMessage.substr(
     alert(strMessage); 
    } 

HTML：

<div class="dynamicDiv"> 
    <input type="text" name="enter_name" id="enter_name" /> 
    <input name="button" id="button" value="Submit" type="button" onclick="addToDiv();"/> 
</div> 

<div id="divName" class="dynamicDiv" style="margin:10px 0px;"> 
<h2>Names List</h2><p>Names of person you've already added.</p> 
</div> 
<div class="dynamicDiv"><input type="button" onclick="displayMessagebye();" value="Loop" /></div> 
<div id="loop" > </div> 
<div class="dynamicDiv"><input type="button" onclick="displayMessage();" value="String" /></div> 
<div id="string" > </div> 

Answer 1

您可以取代過去的 「 」有「。」通過：

strMessage.replace(/, $/, ".") 

Answer 2

爲什麼不只是沒有把它放在那裏擺在首位？

即在此塊：

for(i=0;i<=myNames.length-1;i++) 
{ 
    strMessage = strMessage + myNames[i] + ", " 
} 

只是檢查我們是否是在列表的末尾，把一段有INB地方逗號：

for(i=0;i<=myNames.length-1;i++) 
{ 
    strMessage = strMessage + myNames[i] 
    if(i < myNames.length) 
     strMessage += ","; 
    else 
     strMessage = "."; 
} 

Answer 3

假設你的意思逗號，不常見，請問String.replace(",[^,]+$",".")有效嗎？

請注意，如果您閱讀良好的文檔，則可以在大多數語言中找到相同類型的功能。

Answer 4

您可以使用join加入數組項：

strMessage = myNames.join(", ") 

甚至更​​好：

if (myNames.length <= 1) { 
    strMessage = myNames.join(); 
} else { 
    strMessage = myNames.slice(0, -1).join(", ") + " and " + myNames[myNames.length-1]; 
}