Tab Content Loaded By Default

This might be a trivial question but I would like to know how to have a particular tab opened as the page loads itself. In the following, only the tab menus are there and the conte

Solution 1:

Your can do this in css define your tabcontent first display block as like this

.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>

============ 2nd option is you can deinfe in html by default show to one

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>

Solution 2:

One solution can be to simulate a click.

add this :

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>

Solution 3:

try

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