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Checking if every array element matches a condition

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Posted on Jul 8, 2020

To check if every element matches a condition, arrays in JavaScript have the appropriately named Array.prototype.every().

const isEverybodyOver18 = ages => ages.every(age => age > 18)
 
isEverybodyOver18([27, 35, 52, 91]) // ⇒ true
isEverybodyOver18([16, 23, 42, 19]) // ⇒ false

const isEverybodyOver18 = ages => ages.every(age => age > 18)
 
isEverybodyOver18([27, 35, 52, 91]) // ⇒ true
isEverybodyOver18([16, 23, 42, 19]) // ⇒ false

const isEverybodyOver18 = ages => ages.every(age => age > 18)
 
isEverybodyOver18([27, 35, 52, 91]) // ⇒ true
isEverybodyOver18([16, 23, 42, 19]) // ⇒ false

const isEverybodyOver18 = ages => ages.every(age => age > 18)
 
isEverybodyOver18([27, 35, 52, 91]) // ⇒ true
isEverybodyOver18([16, 23, 42, 19]) // ⇒ false

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Debug

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