Run results for: Testing "prop in obj" vs "obj.prop === undefined" vs hasOwnProperty for undefined member

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/135.0.0.0 Safari/537.36

Browser: Chrome 135

Operating system: Windows

Device Platform: Desktop

Date tested: one year ago

test using in

172.3M/s

test undefined

165.2M/s

test hasOwnProperty

110.6M/s

View exact numbers

Script Preparation code:

var n = {
    a: 13,
    b: [1, 2],
    c: {
        foo: "bar"
    },
    bar: "foo(d)"
}

Tests:

test using in
while(true) { if(!("foo" in n)) break; }
test undefined
var n = {}; while(true) { if(n.foo===undefined) break; }
test hasOwnProperty
var n = {}; while(true) { if(!n.hasOwnProperty('foo')) break; }