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JavaScript empty statement | Basics

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JavaScript empty statement is used to provide no statement, although the JavaScript syntax would expect one. The empty statement is a semicolon (;) indicating that no statement will be executed, even if JavaScript syntax requires one.

;

JavaScript empty statement

Simple example code empty loop body:

<!DOCTYPE html>
<html>
<body>
  <script >
    let arr = [1, 2, 3];

    // Assign all array values to 0
    for (let i = 0; i < arr.length; arr[i++] = 0) 
      /* empty statement */ ;

    console.log(arr);
  </script>
</body>
</html>

Output:

JavaScript empty statement | Basics

If you are looking for JavaScript empty() method then you have to use jQuery empty() Method. The empty() method removes all child nodes and content from the selected elements.

$(selector).empty()

Example

<!DOCTYPE html>
<html>
<head>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.6.0/jquery.min.js"></script>
<script>
$(document).ready(function(){
  $("button").click(function(){
    $("div").empty();
  });
});
</script>
</head>
<body>

<div style="height:100px;background-color:yellow">
  This is some text
  <p>This is a paragraph inside the div.</p>
</div>

<p>This is a paragraph outside the div.</p>

<button>Remove content of the div element</button>

</body>
</html>

What is the point of using empty statements in JavaScript?

Answer: The examples you’ve given don’t make much sense. They should better be written

for (var i = 0; i < a.length;) a[i++] = 0;
for (var i = 0; i < a.length; i++) a[i] = 0;
; // the comparisons really don't do anything (assuming a and b are no objects)
(a==0) || (b = 0); // Oh wait, that's the one given by @Shomz
if (a != 0) b = 0;

However, there are real-world applications for the empty statement. I’ll just list 3 that come to my mind:

  • function x() { … }; A semicolon where it doesn’t belong (e.g. after the function declaration above) makes an empty statement.
  • ; … A leading semicolon on your script files helps to guard against buggy inclusions or file concatenations.
  • while (!check_for_finish()); // do nothing An empty loop body can be used for busy-waiting loops (not recommended) and similar.

Source: stackoverflow.com

Do comment if you have any doubts or suggestions on this Js Basic tutorial.

Note: The All JS Examples codes are tested on the Firefox browser and the Chrome browser.

OS: Windows 10

Code: HTML 5 Version

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