disallow calling global object properties as functions (no-obj-calls)

ECMAScript provides several global objects that are intended to be used as-is. Some of these objects look as if they could be constructors due their capitalization (such as Math and JSON) but will throw an error if you try to execute them as functions.

The ECMAScript 5 specification makes it clear that both Math and JSON cannot be invoked:

The Math object does not have a [[Call]] internal property; it is not possible to invoke the Math object as a function.

Rule Details

This rule disallows calling the Math and JSON objects as functions.

Examples of incorrect code for this rule:

/*eslint no-obj-calls: "error"*/

var math = Math();
var json = JSON();

Examples of correct code for this rule:

/*eslint no-obj-calls: "error"*/

function area(r) {
    return Math.PI * r * r;
var object = JSON.parse("{}");

Further Reading


This rule was introduced in ESLint 0.0.9.