[](https://github.com/droberts-ctrlo/typechecks/actions/workflows/node.js.yml)
npm install @ctrlo/typechecks
This package provides a number of functions to check if a variable in JavaScript or TypeScript is of a certain type.
The available functions are:
usage:
``javascript`
isNotNullOrUndefined(value)
This function checks if a value is not null or undefined and returns true if it is, otherwise false
`javascript`
isNullOrUndefined(value)
This function checks if a value is null or undefined and returns true if it is, otherwise false
usage:
`javascript`
isNull(value)
This function checks if a value is null and returns true if it is, otherwise false
usage:
`javascript`
isUndefined(value)
This function checks if a value is undefined and returns true if it is, otherwise false
usage:
`javascript`
isFinite(value)
This function checks if a value is a number, and if it is finite and returns true if it is, otherwise false
usage:
`javascript`
isInfinite(value)
This function checks if a value is a number, and if it is infinite and returns true if it is, otherwise false
usage:
`javascript`
isInteger(value)
This function checks if a value is an integer and returns true if it is, otherwise false
usage:
`javascript`
isNaN(value)
This function checks if a value is a number, but is a NaN value - it returns true if it is, otherwise false
usage:
`javascript`
isNotInteger(value)
This function checks if a value is a number, but is not an integer and returns true if it is, otherwise false
usage:
`javascript`
isNotNan(value)
This fuction checks if a value is a number, but is not a NaN value - it returns true if it is, otherwise false
usage:
`javascript`
isNumber(value)
This function checks if a value is a number and returns true if it is, otherwise false
usage:
`javascript`
isObject(value)
This function checks if a value is an object and returns true if it is, otherwise false[^1]
usage:
`javascript`
isEmptyOrWhitespace(value)
This function checks if a value is a string, and is empty or whitespace - if it is, it returns true, otherwise false
usage:
`javascript`
isEmptyString(value)
This function checks if a value is a string, but is empty and returns true if it is, otherwise false
usage:
`javascript`
isNotEmptyOrWhitespace(value)
This function checks if a value is a string, and is not empty or whitespace - it returns true if it is, otherwise false
usage:
`javascript`
isNotEmptyString(value)
This function checks if the value is a string and is not empty (but it can be whitespace) - it returns true if it is, otherwise false
usage:
`javascript`
isString(value)
This function checks if the value is a string and returns true if it is, otherwise false
usage:
`javascript`
isArray(value)
This function checks if the value is an array and returns true if it is, otherwise false
usage:
`javascript`
isNumberArray(value)
This function checks if the value is an array of numbers and returns true if it is, otherwise false
usage:
`javascript`
isObjectArray(value)
This function checks if the value is an array of objects and returns true if it is, otherwise false
`javascript`
isStringArray(value)
This function checks if the value is an array of strings and returns true if it is, otherwise false
`javascript`
isBoolean(value)
This function checks if the value is a boolean value and returns true if it is, otherwise false`
[^1]: Assertion of a specific object type is not currently possible