how to use the isundefined function from the lodash library in typescript

To use the isUndefined function from the lodash library in TypeScript, you need to first install the @types/lodash package. This package contains TypeScript definitions for all functions in the lodash library, including isUndefined. You can install it using npm as follows:

npm install --save-dev @types/lodash
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After installing the package, you can import the isUndefined function from the lodash library as follows:

index.ts
import { isUndefined } from 'lodash';

const val: string | undefined = undefined;

if (isUndefined(val)) {
  console.log('Value is undefined');
} else {
  console.log(`Value is ${val}`);
}
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In the example above, we import the isUndefined function from the lodash library and use it to check if a variable val is undefined. If the val is undefined, we print "Value is undefined", otherwise, we print "Value is {val}".

Note that the isUndefined function can also be used with other data types such as numbers, objects, or arrays.