let a = [1,2,3];
let item = a.pop(); // 3
console.log(a); // [1,2]

let a = [1,2,3];
let item = a.shift(); // 1
console.log(a); // [2,3]

let a = [1,2,3];
let item = a.push('end'); 
console.log(a); // [1,2,3,'end']

let a = [1,2,3];
let item = a.unshift('begin'); 
console.log(a); // ['begin',1,2,3]

let a = [1,2,3];
a.reverse(); 
console.log(a); // [3,2,1]

let a = [1, 2, 3, 4, 5, 6, 7];
let item = a.splice(0, 3); // [1,2,3]
console.log(a); // [4,5,6,7]
let item = a.splice(-1, 3); // [7]

let a = [1, 2, 3, 4, 5, 6, 7];
let item = a.splice(0,3,'a'); // [1,2,3]
console.log(a); // ['a',4,5,6,7]
 let b = [1, 2, 3, 4, 5, 6, 7];
let item = b.splice(-2,3,'b','c'); // [6,7]
console.log(b); // [1,2,3,4,5,'b','c']

var a = [10, 1, 3, 20,25,8];
//use toString for sort
console.log(a.sort()) // [1,10,20,25,3,8];

var array = [10, 1, 3, 4,20,4,25,8];
array.sort(function(a,b){
 return a-b;
});
console.log(array); // [1,3,4,4,8,10,20,25];

ES5:
join, toLocateString, toStrigin, slice, cancat, indexOf, lastIndexOf
forEach、every 、some、 fliter、map、reduce、reduceRight、

ES6:
fill, copyWithin
find, findIndex, keys, values, entries


ES7:
includes