Recently I had a string variable but needed to detect if it was present or not for a function that required a boolean.
The !! operator can be applied to a string to determine a boolean where an empty string would return false, and a non-empty string would return true.
// Example string value
var stringValue = "";
// Convert to boolean using double negation operator
var booleanValue = !!stringValue;
// Output the result
console.log(booleanValue); // Output: false
// Example string value
var stringValue = "example";
// Convert to boolean using double negation operator
var booleanValue = !!stringValue;
// Output the result
console.log(booleanValue); // Output: true