javascript - attribute - title html

Contenido de la pestaña cargado por defecto

Question

Esta podría ser una pregunta trivial, pero me gustaría saber cómo abrir una pestaña en particular, ya que la página se carga sola. A continuación, solo aparecen los menús de pestañas y los contenidos se cargan después de hacer clic en cualquiera de las pestañas. En lugar de eso, ¿puedo tener, por ejemplo, el menú de pestañas y el contenido de "Londres" cargados y visibles a medida que se carga la página?

function openCity(evt, cityName) {
    // Declare all variables
    var i, tabcontent, tablinks;

    // Get all elements with class="tabcontent" and hide them
    tabcontent = document.getElementsByClassName("tabcontent");
    for (i = 0; i < tabcontent.length; i++) {
        tabcontent[i].style.display = "none";
    }

    // Get all elements with class="tablinks" and remove the class "active"
    tablinks = document.getElementsByClassName("tablinks");
    for (i = 0; i < tablinks.length; i++) {
        tablinks[i].className = tablinks[i].className.replace(" active", "");
    }

    // Show the current tab, and add an "active" class to the link that opened the tab
    document.getElementById(cityName).style.display = "block";
    evt.currentTarget.className += " active";
}

 /* Style the list */
ul.tab {
    list-style-type: none;
    margin: 0;
    padding: 0;
    overflow: hidden;
    border: 1px solid #ccc;
    background-color: #f1f1f1;
}

/* Float the list items side by side */
ul.tab li {float: left;}

/* Style the links inside the list items */
ul.tab li a {
    display: inline-block;
    color: black;
    text-align: center;
    padding: 14px 16px;
    text-decoration: none;
    transition: 0.3s;
    font-size: 17px;
}

/* Change background color of links on hover */
ul.tab li a:hover {background-color: #ddd;}

/* Create an active/current tablink class */
ul.tab li a:focus, .active {background-color: #ccc;}

/* Style the tab content */
.tabcontent {
    display: none;
    padding: 6px 12px;
    border: 1px solid #ccc;
    border-top: none;
}

 <ul class="tab">
  <li><a href="#" class="tablinks" onclick="openCity(event, ''London'')">London</a></li>
  <li><a href="#" class="tablinks" onclick="openCity(event, ''Paris'')">Paris</a></li>
  <li><a href="#" class="tablinks" onclick="openCity(event, ''Tokyo'')">Tokyo</a></li>
</ul>

<div id="London" class="tabcontent">
  <h3>London</h3>
  <p>London is the capital city of England.</p>
</div>

<div id="Paris" class="tabcontent">
  <h3>Paris</h3>
  <p>Paris is the capital of France.</p>
</div>

<div id="Tokyo" class="tabcontent">
  <h3>Tokyo</h3>
  <p>Tokyo is the capital of Japan.</p>
</div>

Answer 1

Tu puedes hacer esto en css define tu primer display block tabcontent como este

.tabcontent:nth-of-type(1){display:block;}

function openCity(evt, cityName) {
    // Declare all variables
    var i, tabcontent, tablinks;

    // Get all elements with class="tabcontent" and hide them
    tabcontent = document.getElementsByClassName("tabcontent");
    for (i = 0; i < tabcontent.length; i++) {
        tabcontent[i].style.display = "none";
    }

    // Get all elements with class="tablinks" and remove the class "active"
    tablinks = document.getElementsByClassName("tablinks");
    for (i = 0; i < tablinks.length; i++) {
        tablinks[i].className = tablinks[i].className.replace(" active", "");
    }

    // Show the current tab, and add an "active" class to the link that opened the tab
    document.getElementById(cityName).style.display = "block";
    evt.currentTarget.className += " active";
}

 /* Style the list */
ul.tab {
    list-style-type: none;
    margin: 0;
    padding: 0;
    overflow: hidden;
    border: 1px solid #ccc;
    background-color: #f1f1f1;
}

/* Float the list items side by side */
ul.tab li {float: left;}

/* Style the links inside the list items */
ul.tab li a {
    display: inline-block;
    color: black;
    text-align: center;
    padding: 14px 16px;
    text-decoration: none;
    transition: 0.3s;
    font-size: 17px;
}

/* Change background color of links on hover */
ul.tab li a:hover {background-color: #ddd;}

/* Create an active/current tablink class */
ul.tab li a:focus, .active {background-color: #ccc;}

/* Style the tab content */
.tabcontent {
    display: none;
    padding: 6px 12px;
    border: 1px solid #ccc;
    border-top: none;
}
.tabcontent:nth-of-type(1){display:block;}

 <ul class="tab">
  <li><a href="#" class="tablinks" onclick="openCity(event, ''London'')">London</a></li>
  <li><a href="#" class="tablinks" onclick="openCity(event, ''Paris'')">Paris</a></li>
  <li><a href="#" class="tablinks" onclick="openCity(event, ''Tokyo'')">Tokyo</a></li>
</ul>

<div id="London" class="tabcontent">
  <h3>London</h3>
  <p>London is the capital city of England.</p>
</div>

<div id="Paris" class="tabcontent">
  <h3>Paris</h3>
  <p>Paris is the capital of France.</p>
</div>

<div id="Tokyo" class="tabcontent">
  <h3>Tokyo</h3>
  <p>Tokyo is the capital of Japan.</p>
</div>

==================================================================================================================================== La segunda opción es que puedes deinfe en html mostrar por defecto

function openCity(evt, cityName) {
    // Declare all variables
    var i, tabcontent, tablinks;

    // Get all elements with class="tabcontent" and hide them
    tabcontent = document.getElementsByClassName("tabcontent");
    for (i = 0; i < tabcontent.length; i++) {
        tabcontent[i].style.display = "none";
    }

    // Get all elements with class="tablinks" and remove the class "active"
    tablinks = document.getElementsByClassName("tablinks");
    for (i = 0; i < tablinks.length; i++) {
        tablinks[i].className = tablinks[i].className.replace(" active", "");
    }

    // Show the current tab, and add an "active" class to the link that opened the tab
    document.getElementById(cityName).style.display = "block";
    evt.currentTarget.className += " active";
}

 /* Style the list */
ul.tab {
    list-style-type: none;
    margin: 0;
    padding: 0;
    overflow: hidden;
    border: 1px solid #ccc;
    background-color: #f1f1f1;
}

/* Float the list items side by side */
ul.tab li {float: left;}

/* Style the links inside the list items */
ul.tab li a {
    display: inline-block;
    color: black;
    text-align: center;
    padding: 14px 16px;
    text-decoration: none;
    transition: 0.3s;
    font-size: 17px;
}

/* Change background color of links on hover */
ul.tab li a:hover {background-color: #ddd;}

/* Create an active/current tablink class */
ul.tab li a:focus, .active {background-color: #ccc;}

/* Style the tab content */
.tabcontent {
    display: none;
    padding: 6px 12px;
    border: 1px solid #ccc;
    border-top: none;
}

 <ul class="tab">
  <li><a href="#" class="tablinks active" onclick="openCity(event, ''London'')">London</a></li>
  <li><a href="#" class="tablinks" onclick="openCity(event, ''Paris'')">Paris</a></li>
  <li><a href="#" class="tablinks" onclick="openCity(event, ''Tokyo'')">Tokyo</a></li>
</ul>

<div id="London" class="tabcontent" style=display:block;>
  <h3>London</h3>
  <p>London is the capital city of England.</p>
</div>

<div id="Paris" class="tabcontent">
  <h3>Paris</h3>
  <p>Paris is the capital of France.</p>
</div>

<div id="Tokyo" class="tabcontent">
  <h3>Tokyo</h3>
  <p>Tokyo is the capital of Japan.</p>
</div>

Answer 2

Una solución puede ser simular un clic.

Agrega esto :

document.getElementsByClassName("tablinks")[0].click();

function openCity(evt, cityName) {
    // Declare all variables
    var i, tabcontent, tablinks;

    // Get all elements with class="tabcontent" and hide them
    tabcontent = document.getElementsByClassName("tabcontent");
    for (i = 0; i < tabcontent.length; i++) {
        tabcontent[i].style.display = "none";
    }

    // Get all elements with class="tablinks" and remove the class "active"
    tablinks = document.getElementsByClassName("tablinks");
    for (i = 0; i < tablinks.length; i++) {
        tablinks[i].className = tablinks[i].className.replace(" active", "");
    }

    // Show the current tab, and add an "active" class to the link that opened the tab
    document.getElementById(cityName).style.display = "block";
    evt.currentTarget.className += " active";
}

document.getElementsByClassName("tablinks")[0].click();

/* Style the list */
ul.tab {
    list-style-type: none;
    margin: 0;
    padding: 0;
    overflow: hidden;
    border: 1px solid #ccc;
    background-color: #f1f1f1;
}

/* Float the list items side by side */
ul.tab li {float: left;}

/* Style the links inside the list items */
ul.tab li a {
    display: inline-block;
    color: black;
    text-align: center;
    padding: 14px 16px;
    text-decoration: none;
    transition: 0.3s;
    font-size: 17px;
}

/* Change background color of links on hover */
ul.tab li a:hover {background-color: #ddd;}

/* Create an active/current tablink class */
ul.tab li a:focus, .active {background-color: #ccc;}

/* Style the tab content */
.tabcontent {
    display: none;
    padding: 6px 12px;
    border: 1px solid #ccc;
    border-top: none;
}

<ul class="tab">
  <li><a href="#" class="tablinks" onclick="openCity(event, ''London'')">London</a></li>
  <li><a href="#" class="tablinks" onclick="openCity(event, ''Paris'')">Paris</a></li>
  <li><a href="#" class="tablinks" onclick="openCity(event, ''Tokyo'')">Tokyo</a></li>
</ul>

<div id="London" class="tabcontent">
  <h3>London</h3>
  <p>London is the capital city of England.</p>
</div>

<div id="Paris" class="tabcontent">
  <h3>Paris</h3>
  <p>Paris is the capital of France.</p>
</div>

<div id="Tokyo" class="tabcontent">
  <h3>Tokyo</h3>
  <p>Tokyo is the capital of Japan.</p>
</div>

Answer 3

tratar

.tabcontent:first-child{
    display:block;
}