The void keyword in JavaScript ES6 is used to evaluate an expression and it does not return any value. It is a unary operator and takes a single operand. We commonly use it in hyperlinks. Sometimes, we may need to call some JavaScript from a link. When we click on a link, the browser loads a new page or refreshes the same page. But we don’t want that to happen if some JavaScript is attached to that link and the void operator is useful when we have to call another function, which might result in a page refresh.
Syntax:
void (expression) void expression
Below examples illustrate the void keyword in ES6 JavaScript:
Example 1:
HTML
<!DOCTYPE html> < html > < head > < title >ES6 void keyword Example</ title > < style > body{ text-align: center; } h1 { color: green; } </ style > </ head > < body > < h1 >neveropen</ h1 > < b >A Computer Science Portal for Geeks</ b > < br >< br > < a href = "javascript:void(func());" > Click me to activate alert </ a > < br >< br > < a href = "javascript:void(document.body.style.backgroundColor='#F08080');" > Click me to change the background </ a > < script > var func = function() { alert("HI!!!"); }; </ script > </ body > </ html > |
Output:
Example 2:
HTML
<!DOCTYPE html> < html > < head > < title >ES6 void keyword Example</ title > < style > body{ text-align: center; } h1 { color: green; } </ style > </ head > < body > < h1 >neveropen</ h1 > < b >A Computer Science Portal for Geeks</ b > < br >< br > < a href = "javascript:void(javascript:alert('A Computer Science Portal'))" > Click here for no alert </ a > < br >< br > < a href = "javascript:alert('neveropen');" > Click here for an alert </ a > </ body > </ html > |
Output: