isEmpty

Determine if a value is empty

Usage

Pass in a value and get a boolean telling you if the value is empty.

import * as 
import _
_ from 'radashi'

import _
_.
isEmpty<never[]>(value: never[]): value is never[] (+1 overload)
export isEmpty
Return true if the given value is empty.
This function also uses Type Guards to ensure type safety
Empty values include:

null
undefined
0
empty string
empty array
invalid Date time
object with length property of 0
object with size property of 0
object with no enumerable keys
@see ― https://radashi.js.org/reference/typed/isEmpty
@example 
isEmpty(0) // => true
isEmpty(null) // => true
isEmpty(undefined) // => true
isEmpty([]) // => true
isEmpty({}) // => true
@version ― 12.1.0
isEmpty([]) // => true
import _
_.
isEmpty<"">(value: ""): value is "" (+1 overload)
export isEmpty
Return true if the given value is empty.
This function also uses Type Guards to ensure type safety
Empty values include:

null
undefined
0
empty string
empty array
invalid Date time
object with length property of 0
object with size property of 0
object with no enumerable keys
@see ― https://radashi.js.org/reference/typed/isEmpty
@example 
isEmpty(0) // => true
isEmpty(null) // => true
isEmpty(undefined) // => true
isEmpty([]) // => true
isEmpty({}) // => true
@version ― 12.1.0
isEmpty('') // => true

import _
_.
isEmpty<"hello">(value: "hello"): value is never (+1 overload)
export isEmpty
Return true if the given value is empty.
This function also uses Type Guards to ensure type safety
Empty values include:

null
undefined
0
empty string
empty array
invalid Date time
object with length property of 0
object with size property of 0
object with no enumerable keys
@see ― https://radashi.js.org/reference/typed/isEmpty
@example 
isEmpty(0) // => true
isEmpty(null) // => true
isEmpty(undefined) // => true
isEmpty([]) // => true
isEmpty({}) // => true
@version ― 12.1.0
isEmpty('hello') // => false
import _
_.
isEmpty<string[]>(value: string[]): value is never[] (+1 overload)
export isEmpty
Return true if the given value is empty.
This function also uses Type Guards to ensure type safety
Empty values include:

null
undefined
0
empty string
empty array
invalid Date time
object with length property of 0
object with size property of 0
object with no enumerable keys
@see ― https://radashi.js.org/reference/typed/isEmpty
@example 
isEmpty(0) // => true
isEmpty(null) // => true
isEmpty(undefined) // => true
isEmpty([]) // => true
isEmpty({}) // => true
@version ― 12.1.0
isEmpty(['hello']) // => false

Empty values include:

null
undefined
0
empty string
empty array
invalid Date time
object with length property of 0
object with size property of 0
object with no enumerable keys

Type Guards

In some cases, isEmpty acts as a type guard, which helps TypeScript infer more specific types based on the check.

Due to TypeScript limitations, object types cannot be narrowed, except for arrays and functions.

import * as 
import _
_ from 'radashi'

// Example with string
const 
const value1: string
value1: string = ''
if (
import _
_.
isEmpty<string>(value: string): value is "" (+1 overload)
export isEmpty
Return true if the given value is empty.
This function also uses Type Guards to ensure type safety
Empty values include:

null
undefined
0
empty string
empty array
invalid Date time
object with length property of 0
object with size property of 0
object with no enumerable keys
@see ― https://radashi.js.org/reference/typed/isEmpty
@example 
isEmpty(0) // => true
isEmpty(null) // => true
isEmpty(undefined) // => true
isEmpty([]) // => true
isEmpty({}) // => true
@version ― 12.1.0
isEmpty(
const value1: string
value1)) {
  // TypeScript infers value1 as ''
  
var console: Console
The console module provides a simple debugging console that is similar to the
JavaScript console mechanism provided by web browsers.
The module exports two specific components:

A Console class with methods such as console.log(), console.error() and console.warn() that can be used to write to any Node.js stream.
A global console instance configured to write to process.stdout and
process.stderr. The global console can be used without importing the node:console module.

Warning: The global console object's methods are neither consistently
synchronous like the browser APIs they resemble, nor are they consistently
asynchronous like all other Node.js streams. See the note on process I/O for
more information.
Example using the global console:
console.log('hello world');
// Prints: hello world, to stdout
console.log('hello %s', 'world');
// Prints: hello world, to stdout
console.error(new Error('Whoops, something bad happened'));
// Prints error message and stack trace to stderr:
//   Error: Whoops, something bad happened
//     at [eval]:5:15
//     at Script.runInThisContext (node:vm:132:18)
//     at Object.runInThisContext (node:vm:309:38)
//     at node:internal/process/execution:77:19
//     at [eval]-wrapper:6:22
//     at evalScript (node:internal/process/execution:76:60)
//     at node:internal/main/eval_string:23:3

const name = 'Will Robinson';
console.warn(`Danger ${name}! Danger!`);
// Prints: Danger Will Robinson! Danger!, to stderr
Example using the Console class:
const out = getStreamSomehow();
const err = getStreamSomehow();
const myConsole = new console.Console(out, err);

myConsole.log('hello world');
// Prints: hello world, to out
myConsole.log('hello %s', 'world');
// Prints: hello world, to out
myConsole.error(new Error('Whoops, something bad happened'));
// Prints: [Error: Whoops, something bad happened], to err

const name = 'Will Robinson';
myConsole.warn(`Danger ${name}! Danger!`);
// Prints: Danger Will Robinson! Danger!, to err
@see ― source
console.
Console.log(message?: any, ...optionalParams: any[]): void
Prints to stdout with newline. Multiple arguments can be passed, with the
first used as the primary message and all additional used as substitution
values similar to printf(3)
(the arguments are all passed to util.format()).
const count = 5;
console.log('count: %d', count);
// Prints: count: 5, to stdout
console.log('count:', count);
// Prints: count: 5, to stdout
See util.format() for more information.
@since ― v0.1.100
log('Value is an empty string')
} else {
  // TypeScript infers value1 as string
  
var console: Console
The console module provides a simple debugging console that is similar to the
JavaScript console mechanism provided by web browsers.
The module exports two specific components:

A Console class with methods such as console.log(), console.error() and console.warn() that can be used to write to any Node.js stream.
A global console instance configured to write to process.stdout and
process.stderr. The global console can be used without importing the node:console module.

Warning: The global console object's methods are neither consistently
synchronous like the browser APIs they resemble, nor are they consistently
asynchronous like all other Node.js streams. See the note on process I/O for
more information.
Example using the global console:
console.log('hello world');
// Prints: hello world, to stdout
console.log('hello %s', 'world');
// Prints: hello world, to stdout
console.error(new Error('Whoops, something bad happened'));
// Prints error message and stack trace to stderr:
//   Error: Whoops, something bad happened
//     at [eval]:5:15
//     at Script.runInThisContext (node:vm:132:18)
//     at Object.runInThisContext (node:vm:309:38)
//     at node:internal/process/execution:77:19
//     at [eval]-wrapper:6:22
//     at evalScript (node:internal/process/execution:76:60)
//     at node:internal/main/eval_string:23:3

const name = 'Will Robinson';
console.warn(`Danger ${name}! Danger!`);
// Prints: Danger Will Robinson! Danger!, to stderr
Example using the Console class:
const out = getStreamSomehow();
const err = getStreamSomehow();
const myConsole = new console.Console(out, err);

myConsole.log('hello world');
// Prints: hello world, to out
myConsole.log('hello %s', 'world');
// Prints: hello world, to out
myConsole.error(new Error('Whoops, something bad happened'));
// Prints: [Error: Whoops, something bad happened], to err

const name = 'Will Robinson';
myConsole.warn(`Danger ${name}! Danger!`);
// Prints: Danger Will Robinson! Danger!, to err
@see ― source
console.
Console.log(message?: any, ...optionalParams: any[]): void
Prints to stdout with newline. Multiple arguments can be passed, with the
first used as the primary message and all additional used as substitution
values similar to printf(3)
(the arguments are all passed to util.format()).
const count = 5;
console.log('count: %d', count);
// Prints: count: 5, to stdout
console.log('count:', count);
// Prints: count: 5, to stdout
See util.format() for more information.
@since ― v0.1.100
log('Value is a non-empty string')
}

// Example with array
const 
const value2: string[]
value2: string[] = []
if (
import _
_.
isEmpty<string[]>(value: string[]): value is never[] (+1 overload)
export isEmpty
Return true if the given value is empty.
This function also uses Type Guards to ensure type safety
Empty values include:

null
undefined
0
empty string
empty array
invalid Date time
object with length property of 0
object with size property of 0
object with no enumerable keys
@see ― https://radashi.js.org/reference/typed/isEmpty
@example 
isEmpty(0) // => true
isEmpty(null) // => true
isEmpty(undefined) // => true
isEmpty([]) // => true
isEmpty({}) // => true
@version ― 12.1.0
isEmpty(
const value2: string[]
value2)) {
  // TypeScript infers value2 as never[]
  
var console: Console
The console module provides a simple debugging console that is similar to the
JavaScript console mechanism provided by web browsers.
The module exports two specific components:

A Console class with methods such as console.log(), console.error() and console.warn() that can be used to write to any Node.js stream.
A global console instance configured to write to process.stdout and
process.stderr. The global console can be used without importing the node:console module.

Warning: The global console object's methods are neither consistently
synchronous like the browser APIs they resemble, nor are they consistently
asynchronous like all other Node.js streams. See the note on process I/O for
more information.
Example using the global console:
console.log('hello world');
// Prints: hello world, to stdout
console.log('hello %s', 'world');
// Prints: hello world, to stdout
console.error(new Error('Whoops, something bad happened'));
// Prints error message and stack trace to stderr:
//   Error: Whoops, something bad happened
//     at [eval]:5:15
//     at Script.runInThisContext (node:vm:132:18)
//     at Object.runInThisContext (node:vm:309:38)
//     at node:internal/process/execution:77:19
//     at [eval]-wrapper:6:22
//     at evalScript (node:internal/process/execution:76:60)
//     at node:internal/main/eval_string:23:3

const name = 'Will Robinson';
console.warn(`Danger ${name}! Danger!`);
// Prints: Danger Will Robinson! Danger!, to stderr
Example using the Console class:
const out = getStreamSomehow();
const err = getStreamSomehow();
const myConsole = new console.Console(out, err);

myConsole.log('hello world');
// Prints: hello world, to out
myConsole.log('hello %s', 'world');
// Prints: hello world, to out
myConsole.error(new Error('Whoops, something bad happened'));
// Prints: [Error: Whoops, something bad happened], to err

const name = 'Will Robinson';
myConsole.warn(`Danger ${name}! Danger!`);
// Prints: Danger Will Robinson! Danger!, to err
@see ― source
console.
Console.log(message?: any, ...optionalParams: any[]): void
Prints to stdout with newline. Multiple arguments can be passed, with the
first used as the primary message and all additional used as substitution
values similar to printf(3)
(the arguments are all passed to util.format()).
const count = 5;
console.log('count: %d', count);
// Prints: count: 5, to stdout
console.log('count:', count);
// Prints: count: 5, to stdout
See util.format() for more information.
@since ― v0.1.100
log('Value is an empty array')
} else {
  // TypeScript infers value2 as string[]
  
var console: Console
The console module provides a simple debugging console that is similar to the
JavaScript console mechanism provided by web browsers.
The module exports two specific components:

A Console class with methods such as console.log(), console.error() and console.warn() that can be used to write to any Node.js stream.
A global console instance configured to write to process.stdout and
process.stderr. The global console can be used without importing the node:console module.

Warning: The global console object's methods are neither consistently
synchronous like the browser APIs they resemble, nor are they consistently
asynchronous like all other Node.js streams. See the note on process I/O for
more information.
Example using the global console:
console.log('hello world');
// Prints: hello world, to stdout
console.log('hello %s', 'world');
// Prints: hello world, to stdout
console.error(new Error('Whoops, something bad happened'));
// Prints error message and stack trace to stderr:
//   Error: Whoops, something bad happened
//     at [eval]:5:15
//     at Script.runInThisContext (node:vm:132:18)
//     at Object.runInThisContext (node:vm:309:38)
//     at node:internal/process/execution:77:19
//     at [eval]-wrapper:6:22
//     at evalScript (node:internal/process/execution:76:60)
//     at node:internal/main/eval_string:23:3

const name = 'Will Robinson';
console.warn(`Danger ${name}! Danger!`);
// Prints: Danger Will Robinson! Danger!, to stderr
Example using the Console class:
const out = getStreamSomehow();
const err = getStreamSomehow();
const myConsole = new console.Console(out, err);

myConsole.log('hello world');
// Prints: hello world, to out
myConsole.log('hello %s', 'world');
// Prints: hello world, to out
myConsole.error(new Error('Whoops, something bad happened'));
// Prints: [Error: Whoops, something bad happened], to err

const name = 'Will Robinson';
myConsole.warn(`Danger ${name}! Danger!`);
// Prints: Danger Will Robinson! Danger!, to err
@see ― source
console.
Console.log(message?: any, ...optionalParams: any[]): void
Prints to stdout with newline. Multiple arguments can be passed, with the
first used as the primary message and all additional used as substitution
values similar to printf(3)
(the arguments are all passed to util.format()).
const count = 5;
console.log('count: %d', count);
// Prints: count: 5, to stdout
console.log('count:', count);
// Prints: count: 5, to stdout
See util.format() for more information.
@since ― v0.1.100
log('Value is a non-empty array')
}