Concat() Theconcat()method is used to merge two or more arrays and is built directly into the Node.js language. It doesn't change anything about the existing arrays and just simply combines them into one new array. Here's a full example of theconcat()method: Node.js Copy constfirstArr...
const arrayToMap = (arr) => { const mergeObj = (s1, s2) => { const keys = Object.keys(s1); for (const key of keys) { if (typeof s1[key] !== "number" || key === "dept_id") continue; s1[key] += s2[key]; s1[key] /= 2; } }; const map = new Map(); for (...
1.数组合并我们在项目过程中,有时候会遇到需要将两个数组合并成为一个的情况。比如:const a = [1, 2, 3] const b = [4, 5, 6]有两个数组a、b,需求是将两个数组合并成一个。方法如下:1.1 concatconcat方法用于多个数组的合并。它将新数组的成员,添加到原数组成员的后部,然后返回一个新数组,原数组不...
// now walk through the objects in the new array // if the ID exists, then merge the objects. // if the ID does not exist, push to the end of the def array for(var x= 0, l= obj[i].length; x < l; x++) { var newobj = obj[i][x]; if(objids[newobj.id] !== undefin...
JSchallenger-Arrays Get nth element of array# 需求: Write a function that takes an array (a) and a value (n) as argument Return the nth element of 'a' 我的提交(作者答案) functionmyFunction(a, n) {returna[n -1];} 涉及知识(访问数组元素)# ...
The most useful are mergeDeep, getIn, setIn, and updateIn, found on List, Map and OrderedMap.const { fromJS } = require('immutable'); const nested = fromJS({ a: { b: { c: [3, 4, 5] } } }); const nested2 = nested.mergeDeep({ a: { b: { d: 6 } } }); // Map...
varmerge = NS.merge =function( base, extras ){for(varkeyinextras ) {if( extras.hasOwnProperty( key ) ) {if( base.hasOwnProperty( key ) && base[ key ] && extras[ key ] &&typeofbase[ key ] ==='object'&&typeofextras[ key ] ==='object') { merge( base[ key ], extras[ key...
function mergeTwoArrays(array1,array2){ for(let i=0;i<array2.length;i++) { array1.push(array2[i]); } console.log(array1); } mergeTwoArrays([1,2,9,3,5,1,4,5],[11,54,70,40]); mergeTwoArrays([1,2,3],[4,5,6]); Output: [ 1, 2, 9, 3, 5, 1, 4, 5, 11,...
The difference for the immutable collections is that methods which would mutate the collection, likepush,set,unshiftorsplice, instead return a new immutable collection. Methods which return new arrays, likesliceorconcat, instead return new immutable collections. ...
...总结一句就是,用+拼接时,键名一样时只认先出现的(前任),用array_merge拼接时,键名一样时,分键名为数字还是字符串(看脸),数字时不覆盖,字符串时会覆盖原来的值(字符串比较丑,数字比较漂亮)。...+++++ //输出: array(3) { [0]=> string(4) “1003” [1]=> string(4) “1004” [2]=> str...