[英]Finding intersection in multiple arrays
我试图在多个数组中找到相交值,它们在一个对象中,如下所示:
object = {
filterA: ["1","2","3","4"],
filterB: ["2","5","6","7"],
filterN: ["2","4","7"]
}
对象可以包含多个数组,键的名称可以不同。 在描述的对象中,我只需要返回“2”。
我试图建立在这个答案的基础上: javascript 中的多数组交集,但我无法弄清楚,因为它使用静态变量 (a,b,c) 作为示例。 如果有办法用 lodash 做到这一点,我们将不胜感激,但 ES 5 中的 vanilla javascript 也可以!
我有一个简单的单线方法:
const res = Object.values(object).reduce((a, b) => a.filter(i => b.includes(i)))
但是由于您希望在 ES5 (ECMAScript 2009) 版本中使用它,这意味着没有箭头函数、没有 includes() 和没有使用 Set 对象。
const res = Object.values(object).reduce(function (a, b) {
return a.filter(function(i) {
//return b.includes(i);
return b.indexOf(i) >= 0;
});
});
console.log(res);
迭代第一个属性值(数组)并通过与剩余的属性值进行比较来过滤掉。
// get property values(arraya as array)
let arr = Object.values(object);
let res = arr[0]
// iterate over first array
// check value present in remaining object values(arrays)
.filter(v => arr.slice(1).every(a => a.includes(v)));
let object = { filterA: ["1", "2", "3", "4"], filterB: ["2", "5", "6", "7"], filterN: ["2", "4", "7"] }; let arr = Object.values(object); let res = arr[0].filter(v => arr.slice(1).every(a => a.includes(v))); console.log(res)
reduce
将为您完成工作。 在下面查看我的代码。
var object = { filterA: ["1","2","3","4"], filterB: ["2","5","6","7"], filterN: ["2","4","7"] } var res = Object.values(object).reduce(function (acc, array) { return _.intersection(acc, array) }) console.log(res)
<script src="https://cdn.jsdelivr.net/npm/lodash@4.17.11/lodash.min.js"></script>
object = {
filterA: ["1","2","3","4"],
filterB: ["2","5","6","7"],
filterN: ["2","4","7"]
}
let arr = Object.values(object);
let res = arr[0].filter(v => arr.slice(1).every(a => a.includes(v)));
console.log(res)
Lodash 的_.intersection()
可以处理多个数组。 可以创建与函数_.flow()
即得到数组的数组从物体与_.values()
并且通过使用计算的交点_.intersection()
与_.spread()
const { flow, values, spread, intersection } = _ const fn = flow( values, // get the arrays spread(_.intersection) // spread into intersection ) const object = { filterA: ["1","2","3","4"], filterB: ["2","5","6","7"], filterN: ["2","4","7"] } const result = fn(object) console.log(result)
<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.11/lodash.js"></script>
let arrayOfComparisonArrays = [[1,2,3,4,5], [5,3], [1,3,4,5], [5,1,3]]
let intersectionArray
intersectionArray = arrayOfComparisonArrays.reduce((lastArray, nextArray)=>{
let intersection = lastArray.filter(x => nextArray.includes(x))
return intersection
})
//intersectionArray: [ 3, 5 ]
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