After testing for the value, the script prints the evaluation to the screen by modifying the DOM structure shown in Listing 2.

检测完该值后，脚本会通过修改清单2中显示的DOM结构来将这个评估结果显示在屏幕上。

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A particular issue with DOM manipulation is that the browser needs to re-flow and re-paint (basically re-render) the affected elements on the screen.

DOM操作的一个特别问题是浏览器需要在屏幕上回流和重绘(主要是重新呈现)元素。

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