typescript check if is chained code example
Example 1: conditional chaining chrome
const nameLength = db?.user?.name?.length; // property
const adminOption = db?.user?.validateAdminAndGetPrefs?.().option; // functions
const optionLength = db?.user?.preferences?.[optionName].length; // dynamic property
const userName = usersArray?.[userIndex].name; // on arrays
Example 2: optional chaining
/*
* optional chaining (?.) allows me to write code that stops
* running when we encounter a null or undefined value
*/
function tryGetFirstElement<T>(arr?: T[]) {
return arr?.[0];
// equivalent to
// return (arr === null || arr === undefined) ?
// undefined :
// arr[0];
}