How to Ensure Single-Execution of Functions in JavaScript?

Single-Execution Function in JavaScript

In JavaScript, ensuring that a function executes only once can be achieved through various techniques.

Closure-Based Solution

For situations where multiple calls to the function should not trigger its execution, a closure can be employed:

var onceFunction = (function() {
    var alreadyExecuted = false;
    return function() {
        if (!alreadyExecuted) {
            alreadyExecuted = true;
            // Execute the desired actions
        }
    };
})();

onceFunction(); // Executes
onceFunction(); // No execution (alreadyExecuted is true)

Library Function

Several popular JavaScript libraries, such as Underscore and Ramda, provide a convenient utility function named once(). This function accepts a function as an argument and returns a wrapper function that ensures the supplied function is executed only once:

const onceFunction = once(function() { /* Your code here */ });

onceFunction(); // Executes
onceFunction(); // No execution (function is cached)

Custom Utility Function

If external libraries are unavailable, a custom utility function can be created:

const once = (func, context) => {
    let result;
    return () => {
        if (func) {
            result = func.apply(context || this, arguments);
            func = null;
        }
        return result;
    };
};

const oneTimeFunction = once(function() { /* Your code here */ });

oneTimeFunction(); // Executes
oneTimeFunction(); // No execution (function is nullified)

These techniques provide elegant and reliable methods for creating single-execution functions in JavaScript, addressing the requirement stated in the question.

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