ToLength

A method to convert an argument to an integer suitable for use as the length of an array-like object. This method follows ECMAScript's specification for the 'ToLength' abstract operation.

Currently, this module only supports the ES2017 (ES8) specification.

Installation Using npm

npm install es-abstract-to-length

Example Usage

var toLength = require('es-abstract-to-length')

console.log(toLength(-3.14))     // =>    0
console.log(toLength(3.14))      // =>    3
console.log(toLength(42))        // =>   42
console.log(toLength("9001"))    // => 9001
console.log(toLength(null))      // =>    0
console.log(toLength(false))     // =>    0
console.log(toLength(true))      // =>    1

console.log(toLength("foo"))     // =>    0
console.log(toLength({}))        // =>    0
console.log(toLength([]))        // =>    0

console.log(toLength(-Infinity)) // =>    0
console.log(toLength(Infinity))  // => 9007199254740991

Documentation

• API
• ECMAScript Specification References

API

ToLength ( argument )

The abstract operation ToLength converts argument to an integer suitable for use as the length of an array-like object.

A Number value is returned.

A TypeError exception may be thrown for arguments that are Symbols or Objects that lack a valueOf method or a toString method capable of returning a non-object value.

argument

Type: *

The value to convert.

Related Projects

• es-abstract: a single library for multiple ECMAScript abstract operations.