var materials = [
'Hydrogen',
'Helium',
'Lithium',
'Beryllium'
];
console.log(materials.map(material => material.length));
// expected output: Array [8, 6, 7, 9]
var materials = [ 'Hydrogen', 'Helium', 'Lithium', 'Beryllium'];console.log(materials.map(material => material.length));// expected output: Array [8, 6, 7, 9]