[英]Remove elements of an array from another array using javascript
I have two arrays我有两个数组
a[] = [1,2,3,4]
b[] = [1,4]
Need to remove elements of array b from array a.需要从数组 a 中删除数组 b 的元素。
Expected output:预期输出:
a[] = [1,4]
I would use the filter method:我会使用过滤器方法:
a = a.filter(function (item) {
return b.indexOf(item) === -1;
});
const array_diff = (a, b) => a.filter(v => !b.includes(v))
如果你想支持 IE
const array_diff = (a, b) => a.filter(v => b.indexOf(v) === -1);
I'm looping over the second array, and checking if the value is in the first array using indexOf
If it is I use splice
to remove it.我正在遍历第二个数组,并使用
indexOf
检查值是否在第一个数组中,如果是,我使用splice
将其删除。
var a = [1,2,3,4,5];
var b = [3,4,5];
b.forEach(function(val){
var foundIndex = a.indexOf(val);
if(foundIndex != -1){
a.splice(foundIndex, 1);
}
});
Or或者
var a = [1,2,3,4,5];
var b = [3,4,5];
a = a.filter(x => b.indexOf(x) == -1);
For IE 8,对于 IE 8,
for(var i = 0; i < b.length; i++){
var val = b[i];
var foundIndex = a.indexOf(val);
if(foundIndex != -1){
a.splice(foundIndex, 1);
}
}
Take a look at the jQuery docs for $.grep and $.inArray .查看$.grep和$.inArray的 jQuery 文档。
Here's what the code would look like:下面是代码的样子:
var first = [1,2,3,4],
second = [3,4];
var firstExcludeSecond = $.grep(first, function(ele, ix){ return $.inArray(ele, second) === -1; });
console.log(firstExcludeSecond);
Basically amounts to iterating through the first array ($.grep) and determining if a given value is in the second array ($.inArray).基本上相当于遍历第一个数组 ($.grep) 并确定给定值是否在第二个数组 ($.inArray) 中。 If the value returned from $.inArray is -1, the value from the first array does not exist in the second so we grab it.
如果 $.inArray 返回的值为 -1,则第一个数组中的值不存在于第二个数组中,因此我们抓取它。
function myFunction(a, b) {
return a.filter(item => b.indexOf(item) < 0)
}
console.log(myFunction([1, 2, 3], [1, 2]))
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