javascript如何从两个对象数组中找到？

Question

i have two array object

 var data=[{m:1},{m:2},{m:3},{m:4},{m:5},{m:6},{m:7},{m:8},{m:9},{m:10},{m:11},{m:12}];
 var file=[{m:1},{m:3}];

i want to get array like [true,false,false,true,false,false,false,false,false,false,false,false]

Note : in this ayyar it will return true if it match with file array object from data array object.

i try indexOf but i cann't work for my result.

Answer 1

Using Array.prototype.map() and Array.prototype.some() :

  let data = [{m:1},{m:2},{m:3},{m:4},{m:5},{m:6},{m:7},{m:8},{m:9},{m:10},{m:11},{m:12}]; let file = [{m:1},{m:3}]; let result = data.map(d => file.some(f => fm === dm)); console.log(result); 

Answer 2

You could use a hash table and map the occurence.

 var data = [{ m: 1 }, { m: 2 }, { m: 3 }, { m: 4 }, { m: 5 }, { m: 6 }, { m: 7 }, { m: 8 }, { m: 9 }, { m: 10 }, { m: 11 }, { m: 12 }], file = [{ m: 1 }, { m: 3 }], hash = Object.create(null), result; file.forEach(function (a) { hash[am] = true; }); result = data.map(function (a) { return hash[am] || false; }); console.log(result); 

 .as-console-wrapper { max-height: 100% !important; top: 0; } 

ES6 with Set

 var data = [{ m: 1 }, { m: 2 }, { m: 3 }, { m: 4 }, { m: 5 }, { m: 6 }, { m: 7 }, { m: 8 }, { m: 9 }, { m: 10 }, { m: 11 }, { m: 12 }], file = [{ m: 1 }, { m: 3 }], mySet = new Set(file.map(a => am)), result = data.map(a => mySet.has(am)); console.log(result); 

 .as-console-wrapper { max-height: 100% !important; top: 0; } 

Answer 3

Try this Demo

 var data=[{m:1},{m:2},{m:3},{m:4},{m:5},{m:6},{m:7},{m:8},{m:9},{m:10},{m:11},{m:12}]; var file=[{m:1},{m:3}]; var re = []; for(var i=0;i<data.length;i++){ let r = file.find(function findObj(o) { return om === data[i].m; }) if(r){ re.push(true) }else{ re.push(false) } } console.log(re) 

Answer 4

Funny how ridiculously small it becomes with ES6.

Here, file.map(val => val.m) would give me an array of numbers. [1, 3] which I use to find whether it includes current object's m prop.

  var data=[{m:1},{m:2},{m:3},{m:4},{m:5},{m:6},{m:7},{m:8},{m:9},{m:10},{m:11},{m:12}]; var file=[{m:1},{m:3}]; var selection = file.map(val => val.m) var arr = data.map(obj => selection.includes(obj.m)) console.log(arr) 

Answer 5

var data = [{m:1},{m:2},{m:3},{m:4},{m:5},{m:6},{m:7},{m:8},{m:9},{m:10},{m:11},{m:12}];
var file = [{m:1},{m:3}];

var result = [];

function remove_duplicates(data, file) {
    for (var i = 0, len = data.length; i < len; i++) { 
        for (var j = 0, len2 = file.length; j < len2; j++) { 
            if (data[i].m === file[j].m) {
                result.push("true")
            }else{
            result.push("false")
            }
        }
    }
console.log(result)
}

remove_duplicates(data,file);