Class UndefCore

Returns asserts value is T

function add(a: number, b: number): number {
  UndefCore.assertNotNull(a);
  UndefCore.assertNotNull(b);
  return a + b;
}
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Returns asserts value is {}

function add(a: number, b: number): number {
  UndefCore.assertNotNullish(a);
  UndefCore.assertNotNullish(b);
  return a + b;
}
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Returns asserts value is T

function add(a: number, b: number): number {
  UndefCore.assertNotUndefined(a);
  UndefCore.assertNotUndefined(b);
  return a + b;
}
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Returns asserts value is null

const res: null = someCall():
UndefCore.assertNull(res);
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Returns asserts value is null | undefined

const res: null | undefined = someCall():
NullishCore.assertNullish(res);
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Returns asserts value is undefined

const res: undefined = someCall():
UndefCore.assertUndefined(res);
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Returns TypeError

The created error.

Returns value is T

True if the value is neither null nor undefined, otherwise false

const data = ['demo', null, undefined, 'demo'];
const output: (string | undefined)[] = data.filter(UndefCore.isNotNull);
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Returns value is T

True if the value is neither null nor undefined, otherwise false

const data = ['demo', null, undefined, 'demo'];
const output: string[] = data.filter(UndefCore.isNotNullish);
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Returns value is T

True if the value is not undefined, otherwise false

const data = ['demo', undefined, 'demo'];
const output: string[] = data.filter(UndefCore.isNotUndefined);
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Returns value is null

True if the value is null or undefined, otherwise false

const data = ['demo', null, undefined, 'demo'];
const count = data.filter(UndefCore.isNull).length; // 1
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Returns value is null | undefined

True if the value is null or undefined, otherwise false

const data = ['demo', null, undefined, 'demo'];
const count = data.filter(UndefCore.isNullish).length; // 2
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Returns value is undefined

True if the value is undefined, otherwise false

const data = ['demo', undefined, 'demo'];
const count = data.filter(UndefCore.isUndefined).length; // 1
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