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JavaScript: Remove items from a dropdown list

JavaScript DOM: Exercise-8 with Solution

Write a JavaScript program to remove items from a dropdown list.

Sample HTML file:


<!DOCTYPE html>
<html><head>
<meta charset=utf-8 />
<title>Remove items from a dropdown list</title>
</head><body><form>
<select id="colorSelect">
<option>Red</option>
<option>Green</option>
<option>White</option>
<option>Black</option>
</select>
<input type="button" onclick="removecolor()" value="Select and Remove">
</form></body></html>

Sample Solution: -

HTML Code:

<!DOCTYPE html> 
<html> 
<head> 
<style type="text/css"> 
body {margin: 30px;} 
</style>  
<meta charset=utf-8 /> 
<title>Remove items from a dropdown list</title> 
</head><body><form> 
<select id="colorSelect"> 
<option>Red</option> 
<option>Green</option> 
<option>White</option> 
<option>Black</option> 
</select> 
<input type="button" onclick="removecolor()" value="Select and Remove"> 
</form></body></html>

JavaScript Code:

function removecolor()
{
var x=document.getElementById("colorSelect");
x.remove(x.selectedIndex);
}

Sample Output:

javascript-dom-exercise-8

Flowchart:

Flowchart: JavaScript - Remove items from a dropdown list.

Live Demo:

See the Pen javascript-dom-exercise-8 by w3resource (@w3resource) on CodePen.


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Previous: Write a JavaScript function that creates a table, accept row, column numbers from the user, and input row-column number as content (e.g. Row-0 Column-0) of a cell.
Next: Write a JavaScript program to count and display the items of a dropdown list, in an alert window.

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JavaScript: Tips of the Day

JavaScript: semicolon (;)

function nums(a, b) {
  if (a > b) console.log('a is bigger');
  else console.log('b is bigger');
  return;
  a + b;
}

console.log(nums(4, 2));
console.log(nums(1, 2));

In JavaScript, we don't have to write the semicolon (;) explicitly, however the JavaScript engine still adds them after statements. This is called Automatic Semicolon Insertion. A statement can for example be variables, or keywords like throw, return, break, etc.
Here, we wrote a return statement, and another value a + b on a new line. However, since it's a new line, the engine doesn't know that it's actually the value that we wanted to return. Instead, it automatically added a semicolon after return. You could see this as:

return;
a + b;
This means that a + b is never reached, since a function stops running after the return keyword. If no value gets returned, like here, the function returns undefined. Note that there is no automatic insertion after if/else statements!

Ref: https://bit.ly/3jFRBje