Typescript / Angular drill down property checking

Question

Is there a simple generic way in Typescript/Angular to see if a complete path to a property exists and has a value?

For example Could I have a function like

if (thisExists(aaa.bbb.ccc.ddd)) {
 ...
}

Where thisExists would determine somehow that it needs to check

if (aaa == null) return false
if (aaa.bbb == null) return false

etc I know from the html perspective there's a ?. operator, but is there something on the typescript side?

Kiran Shinde · Accepted Answer · 2020-06-30 12:42:42Z

2

You can do something like this, which is called optional chaining

if (aaa?.bbb?.ccc?.ddd) {

answered Jun 30, 2020 at 12:42

Kiran Shinde

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2 Comments

Thanks Kenny, this seems to be correct. I just have to figure out why vscode is flagging it as an error.

@landers are you using resharper? Because it sadly has no support for the latest typescript versions.