Change input value attribute from javascript

Question

I do apologise if this question has been asked but after hours of searching I could not find a solution.

I have a snippet of JavaScript that allows a block of text to be hidden until the user clicks the read more button.

the problem is I need to change the input value attribute after click to read less than to read more after collapse.

JavaScript:

function toggleMe(a){
var e=document.getElementById(a);
if(!e)return true;
if(e.style.display=="none"){
e.style.display="block"
document.getElementsById("toggle").value = "Read Less"
}
else{
e.style.display="none"
document.getElementsById("toggle").value = "Read More"
}
return true;
}

<p>Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.</p>

<div id="Read" style="display:none">
  <p>Contrary to popular belief, Lorem Ipsum is not simply random text. It has roots in a piece of classical Latin literature from 45 BC, making it over 2000 years old. Richard McClintock, a Latin professor at Hampden-Sydney College in Virginia, looked up one of the more obscure Latin words, consectetur, from a Lorem Ipsum passage, and going through the cites of the word in classical literature, discovered the undoubtable source. Lorem Ipsum comes from sections 1.10.32 and 1.10.33 of "de Finibus Bonorum et Malorum" (The Extremes of Good and Evil) by Cicero, written in 45 BC. This book is a treatise on the theory of ethics, very popular during the Renaissance. The first line of Lorem Ipsum, "Lorem ipsum dolor sit amet..", comes from a line in section 1.10.32.</p>
 </div>
<br />
 <input id="toggle" type="button" onclick="return toggleMe('Read')" value="Read More">
 <br />

as you can see from snippet above I am running into a problem where I don't know properly what to change the value="" attribute.

Answer 1

Just a typo:

document.getElementsById()

Should be:

document.getElementById()

Docs here.

When your javascript code doens't works, its a best practice to take a look on your console before anything:

In your case, that is the exception thrown. If you click the right link js:25 it would point straight to the getElementsById function.

Answer 2

function toggleMe(a){
    var e=document.getElementById(a);
    if(!e)return true;
    if(e.style.display=="none"){
        e.style.display="block"
        document.getElementById("toggle").value = "Read Less"
    } else{
        e.style.display="none"
        document.getElementById("toggle").value = "Read More"
    }
    return true;
}

<p>Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.</p>

<div id="Read" style="display:none">
  <p>Contrary to popular belief, Lorem Ipsum is not simply random text. It has roots in a piece of classical Latin literature from 45 BC, making it over 2000 years old. Richard McClintock, a Latin professor at Hampden-Sydney College in Virginia, looked up one of the more obscure Latin words, consectetur, from a Lorem Ipsum passage, and going through the cites of the word in classical literature, discovered the undoubtable source. Lorem Ipsum comes from sections 1.10.32 and 1.10.33 of "de Finibus Bonorum et Malorum" (The Extremes of Good and Evil) by Cicero, written in 45 BC. This book is a treatise on the theory of ethics, very popular during the Renaissance. The first line of Lorem Ipsum, "Lorem ipsum dolor sit amet..", comes from a line in section 1.10.32.</p>
</div>
<br />
<input id="toggle" type="button" onclick="return toggleMe('Read')" value="Read More">
<br />