11th work3

update

标准形式

materials.map(function material){
　　return material.length;
}

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Arrow function restore
var materials = [
'Hydrogen',

'Helium',

'Lithium',

'Beryllium'
];

console.log(materials.map(material => material.length));
写出这个的标准函数形式，就像下面这个形式一样
(var selected = allJobs.filter(function job) {
return job.isSelected();
});

var selected = allJobs.filter(job => job.isSelected());

先画饼。