创建一个函数，该函数接受一个数组并返回一个新数组，其中数字为X的倍数
我可以使用array.splice从数组中删除任何元素
我特意在数组
中查看@ 3和5的倍数应删除X的倍数
3号和5号倍数 我需要为此编写什么方法。我需要使用Vanilla Javascipt
var myArray = [1,2,3,5,9,15,16,21,23,25];
function removeMultiples(ary, num) {
}
//removeMultiples(myArray, 3) => [1,2,5,16,23,25]
//removeMultiples(myArray, 5) => [1,2,3,9,16,21,23]
</script>
3 个答案:
答案 0 :(得分：2)
很好地利用过滤器：
function removeMultiples(arr, mul) {
return arr.filter(function(el) {
return el % mul !== 0;
})
}
或者使用for循环：
function remove(arr, mul) {
var result = [];
for (var i = 0; i < arr.length; i++) {
if (arr[i] % mul) {
result.push(arr[i]);
}
}
return result;
}
答案 1 :(得分：2)
描述
如果使用逗号分隔的字符串（如果是多位数字或带有单个多位数的字符串），则可以使用此正则表达式替换前导逗号，并且可以被3或5整除的数字与null。
(?:,|^)((?:[0369]|[258][0369]*[147]|[147](?:[0369]|[147][0369]*[258])*[258]|[258][0369]*[258](?:[0369]|[147][0369]*[258])*[258]|[147](?:[0369]|[147][0369]*[258])*[147][0369]*[147]|[258][0369]*[258](?:[0369]|[147][0369]*[258])*[147][0369]*[147])*|[0-9]*[50])(?=,|\Z)
可以在此处找到有关此表达式的更详细说明：另请参阅link
替换为： 没有
实施例
现场演示
https://regex101.com/r/iG9lP4/1
示例字符串
1,2,3,5,9,15,16,21,23,25
更换后
1,2,16,23
解释
NODE EXPLANATION
----------------------------------------------------------------------
(?: group, but do not capture:
----------------------------------------------------------------------
, ','
----------------------------------------------------------------------
| OR
----------------------------------------------------------------------
^ the beginning of a "line"
----------------------------------------------------------------------
) end of grouping
----------------------------------------------------------------------
( group and capture to \1:
----------------------------------------------------------------------
(?: group, but do not capture (0 or more
times (matching the most amount
possible)):
----------------------------------------------------------------------
[0369] any character of: '0', '3', '6', '9'
----------------------------------------------------------------------
| OR
----------------------------------------------------------------------
[258] any character of: '2', '5', '8'
----------------------------------------------------------------------
[0369]* any character of: '0', '3', '6', '9'
(0 or more times (matching the most
amount possible))
----------------------------------------------------------------------
[147] any character of: '1', '4', '7'
----------------------------------------------------------------------
| OR
----------------------------------------------------------------------
[147] any character of: '1', '4', '7'
----------------------------------------------------------------------
(?: group, but do not capture (0 or more
times (matching the most amount
possible)):
----------------------------------------------------------------------
[0369] any character of: '0', '3', '6', '9'
----------------------------------------------------------------------
| OR
----------------------------------------------------------------------
[147] any character of: '1', '4', '7'
----------------------------------------------------------------------
[0369]* any character of: '0', '3', '6', '9'
(0 or more times (matching the most
amount possible))
----------------------------------------------------------------------
[258] any character of: '2', '5', '8'
----------------------------------------------------------------------
)* end of grouping
----------------------------------------------------------------------
[258] any character of: '2', '5', '8'
----------------------------------------------------------------------
| OR
----------------------------------------------------------------------
[258] any character of: '2', '5', '8'
----------------------------------------------------------------------
[0369]* any character of: '0', '3', '6', '9'
(0 or more times (matching the most
amount possible))
----------------------------------------------------------------------
[258] any character of: '2', '5', '8'
----------------------------------------------------------------------
(?: group, but do not capture (0 or more
times (matching the most amount
possible)):
----------------------------------------------------------------------
[0369] any character of: '0', '3', '6', '9'
----------------------------------------------------------------------
| OR
----------------------------------------------------------------------
[147] any character of: '1', '4', '7'
----------------------------------------------------------------------
[0369]* any character of: '0', '3', '6', '9'
(0 or more times (matching the most
amount possible))
----------------------------------------------------------------------
[258] any character of: '2', '5', '8'
----------------------------------------------------------------------
)* end of grouping
----------------------------------------------------------------------
[258] any character of: '2', '5', '8'
----------------------------------------------------------------------
| OR
----------------------------------------------------------------------
[147] any character of: '1', '4', '7'
----------------------------------------------------------------------
(?: group, but do not capture (0 or more
times (matching the most amount
possible)):
----------------------------------------------------------------------
[0369] any character of: '0', '3', '6', '9'
----------------------------------------------------------------------
| OR
----------------------------------------------------------------------
[147] any character of: '1', '4', '7'
----------------------------------------------------------------------
[0369]* any character of: '0', '3', '6', '9'
(0 or more times (matching the most
amount possible))
----------------------------------------------------------------------
[258] any character of: '2', '5', '8'
----------------------------------------------------------------------
)* end of grouping
----------------------------------------------------------------------
[147] any character of: '1', '4', '7'
----------------------------------------------------------------------
[0369]* any character of: '0', '3', '6', '9'
(0 or more times (matching the most
amount possible))
----------------------------------------------------------------------
[147] any character of: '1', '4', '7'
----------------------------------------------------------------------
| OR
----------------------------------------------------------------------
[258] any character of: '2', '5', '8'
----------------------------------------------------------------------
[0369]* any character of: '0', '3', '6', '9'
(0 or more times (matching the most
amount possible))
----------------------------------------------------------------------
[258] any character of: '2', '5', '8'
----------------------------------------------------------------------
(?: group, but do not capture (0 or more
times (matching the most amount
possible)):
----------------------------------------------------------------------
[0369] any character of: '0', '3', '6', '9'
----------------------------------------------------------------------
| OR
----------------------------------------------------------------------
[147] any character of: '1', '4', '7'
----------------------------------------------------------------------
[0369]* any character of: '0', '3', '6', '9'
(0 or more times (matching the most
amount possible))
----------------------------------------------------------------------
[258] any character of: '2', '5', '8'
----------------------------------------------------------------------
)* end of grouping
----------------------------------------------------------------------
[147] any character of: '1', '4', '7'
----------------------------------------------------------------------
[0369]* any character of: '0', '3', '6', '9'
(0 or more times (matching the most
amount possible))
----------------------------------------------------------------------
[147] any character of: '1', '4', '7'
----------------------------------------------------------------------
)* end of grouping
----------------------------------------------------------------------
| OR
----------------------------------------------------------------------
[0-9]* any character of: '0' to '9' (0 or more
times (matching the most amount
possible))
----------------------------------------------------------------------
[50] any character of: '5', '0'
----------------------------------------------------------------------
) end of \1
----------------------------------------------------------------------
(?= look ahead to see if there is:
----------------------------------------------------------------------
, ','
----------------------------------------------------------------------
| OR
----------------------------------------------------------------------
\Z before an optional \n, and the end of
the string
----------------------------------------------------------------------
) end of look-ahead
----------------------------------------------------------------------
答案 2 :(得分：1)
这听起来像是家庭作业。这是一个不依赖于Array.prototype.filter内置方法的家庭作业答案。这个简单的递归定义使用恒定的时间和空间。
const removeMultiples = (n, xs)=> {
let loop = (ys, xs)=> {
if (xs.length === 0)
return ys;
else if (xs[0] % n === 0)
return loop(ys, xs.slice(1));
else
return loop(ys.concat([xs[0]]), xs.slice(1));
};
return loop([], xs);
};
removeMultiples(3, [0,1,2,3,4,5,6,7,8,9]);
//=> [1,2,4,5,7,8]
这使用了Array.prototype.filter，可能并没有教会你什么。
myArray.filter(x=> x % 3 !== 0);
myArray.filter(x=> x % 5 !== 0);
这使用简单函数的组合来实现您的目标。这种方法的好处是每个函数都做一个简单的事情，每个函数都是高度可重用的。
// (b->c) -> (a->b) -> (a->c)
const comp = f=> g=> x=> f (g (x));
// Boolean -> Boolean
const not = x=> !x;
// Number -> Number -> Boolean
const isDivisibleBy = x=> y=> y % x === 0;
// Array -> Boolean
const isEmpty = xs=> xs.length === 0;
// [Value] -> Value
const first = xs=> xs[0];
// [Value] -> [Value]
const rest = xs=> xs.slice(1);
// [Value] -> [Value] -> [Value]
const concat = xs=> ys=> ys.concat(xs);
// Value -> [Value] -> [Value]
const append = x=> concat([x]);
// (a->b->a) -> a -> [b] -> a
const reduce = f=> y=> xs=>
isEmpty(xs) ? y : reduce (f) (f (y) (first (xs))) (rest (xs));
// (Value->Boolean) -> [Value] -> [Value]
const filter = f=>
reduce (ys=> x=> f (x) ? append (x) (ys) : ys) ([]);
// Number -> [Number] -> [Number]
const removeMultiples = x=>
filter (comp (not) (isDivisibleBy(x)));
好的，现在让我们看看所有功能协调一致！
removeMultiples (3) ([1,2,3,5,9,15,16,21,23,25]);
//=> [ 1, 2, 5, 16, 23, 25 ]
removeMultiples (5) ([1,2,3,5,9,15,16,21,23,25]);
//=> [ 1, 2, 3, 9, 16, 21, 23 ]
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