我想了解从另一个数组的所有元素中过滤一个数组的最佳方法。我尝试了过滤功能,但它不来我如何给它的值,我想删除。喜欢的东西:
var array = [1,2,3,4];
var anotherOne = [2,4];
var filteredArray = array.filter(myCallback);
// filteredArray should now be [1,3]
function myCallBack(){
return element ! filteredArray;
//which clearly can't work since we don't have the reference <,<
}
如果过滤器函数没有用处,您将如何实现它?
编辑:我检查了可能的重复问题,这可能对那些容易理解javascript的人有用。如果答案勾选“好”,事情就简单多了。
/* Here's an example that uses (some) ES6 Javascript semantics to filter an object array by another object array. */
// x = full dataset
// y = filter dataset
let x = [
{"val": 1, "text": "a"},
{"val": 2, "text": "b"},
{"val": 3, "text": "c"},
{"val": 4, "text": "d"},
{"val": 5, "text": "e"}
],
y = [
{"val": 1, "text": "a"},
{"val": 4, "text": "d"}
];
// Use map to get a simple array of "val" values. Ex: [1,4]
let yFilter = y.map(itemY => { return itemY.val; });
// Use filter and "not" includes to filter the full dataset by the filter dataset's val.
let filteredX = x.filter(itemX => !yFilter.includes(itemX.val));
// Print the result.
console.log(filteredX);
来自另一个包含对象属性的数组的更灵活的过滤数组
function filterFn(array, diffArray, prop, propDiff) {
diffArray = !propDiff ? diffArray : diffArray.map(d => d[propDiff])
this.fn = f => diffArray.indexOf(f) === -1
if (prop) {
return array.map(r => r[prop]).filter(this.fn)
} else {
return array.filter(this.fn)
}
}
//You can use it like this;
var arr = [];
for (var i = 0; i < 10; i++) {
var obj = {}
obj.index = i
obj.value = Math.pow(2, i)
arr.push(obj)
}
var arr2 = [1, 2, 3, 4, 5]
var sec = [{t:2}, {t:99}, {t:256}, {t:4096}]
var log = console.log.bind(console)
var filtered = filterFn(arr, sec, 'value', 't')
var filtered2 = filterFn(arr2, sec, null, 't')
log(filtered, filtered2)