effect description: each time you add the + button, you can add a new row of new columns, and click the following to delete the row.
:,.
:
cause analysis: react"s diff algorithm needs to add key values to nodes to recognize different nodes, so add key values to nodes.
result: adding key values is still invalid.
index is not allowed, because the current key has been refreshed before diff.
you can take a look at my blog
uses WeakMap to assign objects in Vue's new array: key
when adding, generate a unique key, for the newly added object. Do not use index.
{key: Date.now()} id attribute to each item in data . Each time you click the + button to add a new line, set the id of the row corresponding to item to Date.now () ; < div key= {String (index*44)} > to < div key= {item.id} > ; < InputNumber key= {String (index*34)} > to < InputNumber > (not key ). Previous: How to make the web page support both mobile and computer versions in the mobile phone?
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