I have an avatar that shows the first letter of the user's first name. The list of user name es when the API call. If the API call not happened TypeError: Cannot read property 'charAt' of undefined error ing as there is no in put json. My react code as follows.
<Avatar
style={{ color: "#ffffff", backgroundColor: "#5e206e" }}
>
{item.user != null ? item.user.charAt(0) : "UU"}
</Avatar>
I have an avatar that shows the first letter of the user's first name. The list of user name es when the API call. If the API call not happened TypeError: Cannot read property 'charAt' of undefined error ing as there is no in put json. My react code as follows.
<Avatar
style={{ color: "#ffffff", backgroundColor: "#5e206e" }}
>
{item.user != null ? item.user.charAt(0) : "UU"}
</Avatar>
1 Answer
Reset to default 2User can still be undefined and throw error. I would also check first for user.
I suggest to use Optional Chaining introduced in ES2020.
<Avatar style={{ color: "#ffffff", backgroundColor: "#5e206e" }}>
{item?.user ? item.user.charAt(0) : "UU"}
</Avatar>
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