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JavaScript - check if function is arrow function
7 points
In this short article, we would like to show how to check if function is arrow function in JavaScript.
Quick solution:
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const isArrowFunction = (variable) => {2
if (typeof variable=== 'function') {3
const source = variable.toString();4
return /^\([^)]*\)\s*=>/.test(source);5
}6
return false;7
};8
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// Usage example:11
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console.log(isArrowFunction(() => {})); // true13
console.log(isArrowFunction((arg1, arg2, arg3) => {})); // true14
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console.log(isArrowFunction(function() {})); // false16
console.log(isArrowFunction(function action() {})); // falseWarning: be careful, some transpilers may convert functions types depending on target (ES3, ES5, ES6, etc.).
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const isArrowFunction = (variable) => {2
if (typeof variable === 'function') {3
return !variable.prototype;4
}5
return false;6
};7
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// Usage example:10
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console.log(isArrowFunction(() => {})); // true12
console.log(isArrowFunction((arg1, arg2, arg3) => {})); // true13
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console.log(isArrowFunction(function() {})); // false15
console.log(isArrowFunction(function action() {})); // false
