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JavaScript Array copyWithin() 方法


实例

将前两个数组元素复制到最后两个数组元素:

var fruits = ["Banana", "Orange", "Apple", "Mango"];
fruits.copyWithin(2, 0);
亲自试一试 »

页面下方有更多实例。


定义和用法

copyWithin() 方法将数组元素复制到数组中的另一个位置,覆盖现有值。

copyWithin() 方法永远不会向数组添加更多项。

提示:copyWithin() 方法会覆盖原始数组。


浏览器支持

表中的数字表示支持该方法的第一个浏览器版本。

方法
copyWithin() 45.0 12.0 32.0 9 32.0

语法

array.copyWithin(target, start, end)

参数值

参数 描述
target 必需。将元素复制到的索引位置。
start 可选。开始复制元素的索引位置(默认为 0)。
end 可选。停止从中复制元素的索引位置(默认为 array.length)。

技术细节

返回值: 数组,被改变的数组。
JavaScript 版本: ECMAScript 6

更多实例

实例

将前两个数组元素复制到第三和第四个位置:

var fruits = ["Banana", "Orange", "Apple", "Mango", "Kiwi", "Papaya"];
fruits.copyWithin(2, 0, 2);
亲自试一试 »

相关页面

JavaScript 教程: JavaScript 数组


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