![js中有["1","2","3","4"]这样一个string，怎么把它变成array](/aiimages/js%E4%B8%AD%E6%9C%89%5B%26quot%3B1%26quot%3B%2C%26quot%3B2%26quot%3B%2C%26quot%3B3%26quot%3B%2C%26quot%3B4%26quot%3B%5D%E8%BF%99%E6%A0%B7%E4%B8%80%E4%B8%AAstring%EF%BC%8C%E6%80%8E%E4%B9%88%E6%8A%8A%E5%AE%83%E5%8F%98%E6%88%90array.png)
js常用排序实现，参考代码如下
<script>Array.prototype.swap = function(i, j)
{
var temp = this[i]
this[i] = this[j]
this[j] = temp
}
Array.prototype.bubbleSort = function()
{
for (var i = this.length - 1 i > 0 --i)
{
for (var j = 0 j < i ++j)
{
if (this[j] > this[j + 1]) this.swap(j, j + 1)
}
}
}
Array.prototype.selectionSort = function()
{
for (var i = 0 i < this.length ++i)
{
var index = i
for (var j = i + 1 j < this.length ++j)
{
if (this[j] < this[index]) index = j
}
this.swap(i, index)
}
}
Array.prototype.insertionSort = function()
{
for (var i = 1 i < this.length ++i)
{
var j = i, value = this[i]
while (j > 0 && this[j - 1] > value)
{
this[j] = this[j - 1]
--j
}
this[j] = value
}
}
Array.prototype.shellSort = function()
{
for (var step = this.length >> 1 step > 0 step >>= 1)
{
for (var i = 0 i < step ++i)
{
for (var j = i + step j < this.length j += step)
{
var k = j, value = this[j]
while (k >= step && this[k - step] > value)
{
this[k] = this[k - step]
k -= step
}
this[k] = value
}
}
}
}
Array.prototype.quickSort = function(s, e)
{
if (s == null) s = 0
if (e == null) e = this.length - 1
if (s >= e) return
this.swap((s + e) >> 1, e)
var index = s - 1
for (var i = s i <= e ++i)
{
if (this[i] <= this[e]) this.swap(i, ++index)
}
this.quickSort(s, index - 1)
this.quickSort(index + 1, e)
}
Array.prototype.stackQuickSort = function()
{
var stack = [0, this.length - 1]
while (stack.length > 0)
{
var e = stack.pop(), s = stack.pop()
if (s >= e) continue
this.swap((s + e) >> 1, e)
var index = s - 1
for (var i = s i <= e ++i)
{
if (this[i] <= this[e]) this.swap(i, ++index)
}
stack.push(s, index - 1, index + 1, e)
}
}
Array.prototype.mergeSort = function(s, e, b)
{
if (s == null) s = 0
if (e == null) e = this.length - 1
if (b == null) b = new Array(this.length)
if (s >= e) return
var m = (s + e) >> 1
this.mergeSort(s, m, b)
this.mergeSort(m + 1, e, b)
for (var i = s, j = s, k = m + 1 i <= e ++i)
{
b[i] = this[(k > e || j <= m && this[j] < this[k]) ? j++ : k++]
}
for (var i = s i <= e ++i) this[i] = b[i]
}
Array.prototype.heapSort = function()
{
for (var i = 1 i < this.length ++i)
{
for (var j = i, k = (j - 1) >> 1 k >= 0 j = k, k = (k - 1) >> 1)
{
if (this[k] >= this[j]) break
this.swap(j, k)
}
}
for (var i = this.length - 1 i > 0 --i)
{
this.swap(0, i)
for (var j = 0, k = (j + 1) << 1 k <= i j = k, k = (k + 1) << 1)
{
if (k == i || this[k] < this[k - 1]) --k
if (this[k] <= this[j]) break
this.swap(j, k)
}
}
}
function generate()
{
var max = parseInt(txtMax.value), count = parseInt(txtCount.value)
if (isNaN(max) || isNaN(count))
{
alert("个数和最大值必须是一个整数")
return
}
var array = []
for (var i = 0 i < count ++i) array.push(Math.round(Math.random() * max))
txtInput.value = array.join("\n")
txtOutput.value = ""
}
function demo(type)
{
var array = txtInput.value == "" ? [] : txtInput.value.replace().split("\n")
for (var i = 0 i < array.length ++i) array[i] = parseInt(array[i])
var t1 = new Date()
eval("array." + type + "Sort()")
var t2 = new Date()
lblTime.innerText = t2.valueOf() - t1.valueOf()
txtOutput.value = array.join("\n")
}
</script>
<body onload=generate()>
<table style="width:100%height:100%font-size:12pxfont-family:宋体">
<tr>
<td align=right>
<textarea id=txtInput readonly style="width:100pxheight:100%"></textarea>
</td>
<td width=150 align=center>
随机数个数<input id=txtCount value=500 style="width:50px"><br><br>
最大随机数<input id=txtMax value=1000 style="width:50px"><br><br>
<button onclick=generate()>重新生成</button><br><br><br><br>
耗时(毫秒)：<label id=lblTime></label><br><br><br><br>
<button onclick=demo("bubble")>冒泡排序</button><br><br>
<button onclick=demo("selection")>选择排序</button><br><br>
<button onclick=demo("insertion")>插入排序</button><br><br>
<button onclick=demo("shell")>谢尔排序</button><br><br>
<button onclick=demo("quick")>快速排序(递归)</button><br><br>
<button onclick=demo("stackQuick")>快速排序(堆栈)</button><br><br>
<button onclick=demo("merge")>归并排序</button><br><br>
<button onclick=demo("heap")>堆排序</button><br><br>
</td>
<td align=left>
<textarea id=txtOutput readonly style="width:100pxheight:100%"></textarea>
</td>
</tr>
</table>
</body>
你好，给你写了一个很基础的例子。参照着自己优化成你想要的效果吧。
示例是这样的，鼠标移动到div上，背景图片会从左往右移动直至最右端。鼠标移出div，背景图标从右往左直至最左端。
备注：考虑到宽度变化，本例背景图片使用百分比定位。根据你的实际情况也可改为使用像素(px)定位。
<style>.bg-div {
height: 110px
background: url(https://gss0.bdstatic.com/7Ls0a8Sm1A5BphGlnYG/sys/portrait/item/27267a776a746b7505.jpg) 0% center no-repeat #ccc
}
</style>
<div id="J_BgDiv" class="bg-div"></div>
<script>
(function() {
var div = document.getElementById('J_BgDiv')
// 背景百分比（从左至右，0%-100%）
var pos = 0
// 背景向右移还是向左移（0：向右，1：向左）
var dir = 0
// 每次移动的百分比，控制速度
var step = 3
div.addEventListener('mouseover', function() {
var node = div
dir = 0
if (!div.mover) {
div.mover = setInterval(function() {
// 每次移动10%
if (dir === 0) {
pos += step
} else {
pos -= step
}
pos = pos >= 100 ? 100 : pos
pos = pos <= 0 ? 0 : pos
node.style.backgroundPosition = pos + '% center'
}, 20)
}
}, false)
div.addEventListener('mouseout', function() {
dir = 1
}, false)
})()
</script>
希望能帮你解决问题，如有疑问可以追问。
