Elements

Indexed properties in javascript are called elements and are treated separately from the named properties They are mostly prominent in arrays and used for different prototype method.

Run

   d8 --allow-natives-syntax element-transition.js

Output

01. Packed SMI Elements

const array = [1, 2, 3];

02. Packed Double Elements

array.push(4.44);

03. Packed Elements

array.push('x');

04. Holey SMI Elements

const newArray = [1, 2, 3];
delete newArray[1];

05. Holey SMI Elements

newArray[1] = 2;

Once hole is created it cannot be reverted back.

06. Holey Double Elements

newArray.push(3.33);

07. Holey Elements

newArray.push('x');