https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/prototype
//arrow function example
var materials = [
"Hydrogen",
"Helium",
"Lithium",
"Beryllium"
];
var materialsLength1 = materials.map(function(material){
return material.length
});
var materialsLength2 = materials.map((material)=>{
return material.length
});
var materialsLength3 = materials.map(material=> material.length);
