JavaScript 将数组分成两半，将前半部分与后半部分并列

Question

将数组平均分成两个的方法是什么？ 然后，将后半部分放在第一个 all 下方，以比较新的最终阵列是否应该在插槽中接收零或一。

var master_array = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38];

var first_half = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19];

var second_half = [20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38];

var final_usable_array_reduced = [];

因此，给定一个包含 38 个复选框的表单，如果选中第 5、19、37 和 38 个复选框，则final_usable_array_reduced为

final_usable_array_reduced = [0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1];

final_usable_array_reduced[4] = **represents the 5th <strong>or</strong> 24th box being checked**

final_usable_array_reduced[18] = **represents the 19th <strong>or</strong> 38th boxes being checked**

Answer 1

我认为你可以通过一个简单的for循环来实现这一点，超过一半的master_array，or数组下半部分的值与上半部分的值：

var master_array = new Array(38).fill(0);
master_array[4] = 1;
master_array[18] = 1;
master_array[36] = 1;
master_array[37] = 1;
let len = master_array.length / 2;
final_usable_array_reduced = new Array(len);
for (let i = 0; i < len; i++) {
final_usable_array_reduced[i] = master_array[i] | master_array[i + len];
}
console.log(final_usable_array_reduced);

Answer 2

检查这个：

var array = [0,0,0,0,1,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0];
var firstHalf = array.slice(0,array.length/2);
var secondHalf = array.slice(array.length/2);
var result = firstHalf.map(function(e,i){
return e || secondHalf[i];
});
console.log(result);

我在这里所做的是用slice将数组分成两半(当然，考虑到数组元素是偶数(，然后我映射第一个返回 1(或 true，是相同的(，如果firstArray[i]或secondArray[1]是 1。

Answer 3

请考虑以下几点。

$(function() {
function addChecks(count, tObj, cont) {
var i;
if (cont == undefined) {
i = 0;
} else {
i = parseInt($("input:last").val()) - 1;
count = i + count;
}
for (i; i <= count; i++) {
$("<input>", {
type: "checkbox",
value: (i + 1),
title: (i + 1)
}).appendTo(tObj);
}
}
function checksToArray() {
var arr = [];
$("input[type='checkbox']").each(function() {
arr.push($(this).prop("checked"));
});
return arr;
}
function compHalfArr(a) {
var arr = [];
var h = Math.floor(a.length / 2);
for (var i = 0; i <= h; i++) {
arr.push(a[i] || a[(i + h)]);
}
return arr;
}
addChecks(14, $(".section-1"));
addChecks(14, $(".section-2"), true);
$("button").click(function() {
var allChecks = checksToArray();
var compChecks = compHalfArr(allChecks);
$(".results").html("<span>" + compChecks.join("</span><span>") + "</span>").find("span:last").remove();
});
});

.checks input {
margin-right: 20px;
}
.results span {
display: inline-block;
font-family: Arial, sans-serif;
width: 40px;
text-align: center;
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div class="checks section-1"></div>
<div class="checks section-2"></div>
<button>Check</button>
<div class="results"></div>

您可以使用中间标记进行循环。