Any

As explained in Secrets of the JavaScript Ninja, Second Edition

An Array method that returns true if at least one element passes a callback test.

const ninjas = [
  {name: "Yagyu", weapon: "shuriken"},
  {name: "Yoshi" },
  {name: "Kuma", weapon: "wakizashi"}
];

const allNinjasAreNamed = ninjas.every(ninja => "name" in ninja);       #A
const allNinjasAreArmed = ninjas.every(ninja => "weapon" in ninja);     #A

assert(allNinjasAreNamed, "Every ninja has a name");
assert(!allNinjasAreArmed, "But not every ninja is armed");

const someNinjasAreArmed = ninjas.some(ninja => "weapon" in ninja);     #B
assert(someNinjasAreArmed, "But some ninjas are armed");                #B

How Secrets of the JavaScript Ninja, Second Edition covers it

How deep it goes

Defines the callback test with a concrete example, without detailing execution mechanics.

Examples

Checks whether any ninja object has a weapon property.

What you can do after

Apply JavaScript's Array some method to test whether any item meets a condition.

How it connects

Pairs some with every for testing array items against conditions.

liveBookmanning.com

Read Secrets of the JavaScript Ninja, Second Edition on liveBook Get the book at manning.com

Also explained in

• 

  liveBookmanning.com
  Kotlin in Action, 2Eany is a Kotlin standard-library operation that returns true when at least one element in a collection satisfies a predicate.

Compare how 2 books explain any →

Related concepts

• equality by valuehas part · Equality by value is an equality semantics in which values are considered equal when they represent equivalent contents, regardless of object identity.
• allcontrasts with · An all operation returns a Boolean indicating whether every item in a collection satisfies a condition, or is truthy when no condition is specified.
• Objectequivalent to · java.lang.Object is the root class of Java’s reference-type hierarchy and defines methods inherited by Java reference types.
• logical ORequivalent to · Logical OR is a Boolean disjunction that evaluates to true when at least one operand or condition is true.
• listuses · A list is an ordered collection of elements arranged in a sequence.

This explainer was generated by Manning's knowledge graph from the text of Secrets of the JavaScript Ninja, Second Edition. The section links point to the parts of the book it draws on.