Question

我有以下代码：

process.on("message", function(data){
    if(data.cmd === "BROADCAST_TO_WORKER"){



    io.sockets.emit("SERVER_MESSAGE", { message: data.message, reload: data.reload, player_id : data.player_id });
}
});

我想在数组的开头多次添加var foo = 'foo' var bar = 'bar' var arr = [1,2,3]，在数组的末尾添加foo。每个元素添加的次数应该是动态的，结果数组应该是这样的：

bar

有没有比为每个元素使用循环更好的方法？如果需要，我可以使用lodash。

Answer 1

如果更好意味着更短，是的还有一种方法：

forloop

Answer 2

试试这个push方法。 Array#unshift()在数组的开头添加了值。var foo = 'foo' var bar = 'bar' var arr = [1,2,3] for(var i=0; i<(Math.random() * 5); i++){ arr.unshift(foo) } for(var i=0; i<(Math.random() * 5); i++){ arr.push(bar) } console.log(arr)添加了数组的结尾

＆＃13;

<!-- HEADER -->
<header id="header" class="header-left">        
    <div class="header-inner clearfix">

        <!-- LOGO -->
        <div id="logo" class="logo-left">
            <a href="index.html">
                     <img id="dark-logo" src="files/uploads/logo_dark.png" srcset="files/uploads/logo_dark.png 1x, files/uploads/logo_dark@2x.png 2x" alt="Logo Dark">
                     <img id="light-logo" src="files/uploads/logo_light.png" srcset="files/uploads/logo_light@2x.png 1x, files/uploads/logo_light@2x.png 2x" alt="Logo Light">
            </a>
        </div>

        <!-- MAIN NAVIGATION -->
        <div id="menu" class="clearfix">            

            <div class="menu-actions">
                <div class="menu-toggle"><span class="hamburger"></span></div>
            </div> <!-- END .menu-actions -->

            <div id="menu-inner">
                <nav id="main-nav">
                    <ul>
                        <li><a href="index.html">xxx</a>
                        </li>
                        <li><a href="#">xxx</a>
                        <ul class="sub-menu">
                        <li><a href="xxx.html">xxx</a></li>
                        <li><a href="xxx.html">xxxx</a></li>
                        <li><a href="xxx.html">xxx</a></li>
                        </ul>
                        </li>
                    </ul>
                </nav>
            </div>
        </div>
     </div>
    <span class="pseudo-close header-close"></span>
</header>

＆＃13;

Answer 3

您可以使用unshift和push

function pushToBeginning(arr, str, count){
    while(count--){
        arr.unshift(str);
    }
}

function pushToEnd(arr, str, count){
    while(count--){
        arr.push(str);
    }
}

let arr = [1, 2, 3];

pushToBeginning(arr, 'Foo', 3);
pushToEnd(arr, 'Bar', 2);

console.log(arr);

Answer 4

或类似的东西。

<android.support.design.widget.TextInputLayout
            android:textColorHint="#404040"    // Change color as per your wish
            android:layout_width="match_parent"
            android:layout_height="wrap_content">

        <EditText
                android:layout_width = "match_parent"
                android:layout_height = "wrap_content"
                android:hint ="Email"
                android:maxLines="1"
                android:textColor="#000000" />

    </android.support.design.widget.TextInputLayout>

    <android.support.design.widget.TextInputLayout
            android:layout_marginTop="10dp"
            android:textColorHint="#404040"    // Change color as per your wish
            android:layout_width="match_parent"
            android:layout_height="wrap_content">

        <EditText android:layout_width="match_parent"
                  android:layout_height="wrap_content"
                  android:id="@+id/passwordText"
                  android:hint="Password"
                  android:maxLines="1"
                  android:textColor="#000000"
                  android:inputType="textPassword"/>

    </android.support.design.widget.TextInputLayout>

Javascript多次推送/移动相同的元素

4 个答案: