JavaScript: Returns true if the provided predicate function returns true for all elements in a collection, false otherwise
JavaScript fundamental (ES6 Syntax): Exercise-16 with Solution
Write a JavaScript function that returns true if the provided predicate function returns true for all elements in a collection, false otherwise.
- Use Array.prototype.every() to test if all elements in the collection return true based on fn.
- Omit the second argument, fn, to use Boolean as a default.
Sample Solution:
JavaScript Code:
//#Source https://bit.ly/2neWfJ2
const all = (arr, fn = Boolean) => arr.every(fn);
console.log(all([4, 2, 3], x => x > 1));
console.log(all([4, 2, 3], x => x < 1));
console.log(all([1, 2, 3]));
Sample Output:
true false true
Flowchart:

Live Demo:
See the Pen javascript-basic-exercise-1-16 by w3resource (@w3resource) on CodePen.
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Previous: Write a JavaScript program to return the minimum-maximum value of an array, after applying the provided function to set comparing rule.
Next: Write a JavaScript program to split values of two given arrays into two groups. If an element in filter is truthy, the corresponding element in the collection belongs to the first group; otherwise, it belongs to the second group.
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