First of all, there is no document resource by default, so you need to download it yourself. The steps are as follows:

Edit-option, first set the location of the document in the first tab. Set the network options in the second tab.

Select to download a document in the third tab. First, select the document to download from the list below, and then click Download. Click OK and wait for the download to complete.

After the download is completed, it will be displayed in the main interface.

Just enter what you want to query in the input box in the upper left corner.

If you have more than one docset, you can also add php:mysqli_query in front of it, which will search php docset.

Zeal will search all local docset according to the text you enter, and the list on the left shows all the options. The following list shows the item where the cursor is located, the section where he is located, and my understanding is all the methods and functions of his class.

Moreover, the style of the webpage is very similar to various languages and frameworks in official website. All right, study hard.