| Function Name | Parameter Types | Return Types | Function Description | | --- | --- | --- | --- | | roundToDecimal | (num: number, digit: number) | number | Rounds a number to a specified number of decimal places | | sumArray | (nums: unknown[]) | number | null | Sums an array of numbers, considering decimal places | | multiplyArray | (nums: unknown[]) | number | null | Multiplies an array of numbers, considering decimal places | | pickProps | (obj: Record, keys: keyof T[]) | Pick | Picks specified properties from an object | | omitProps | (obj: Record, keys: keyof T[]) | Omit | Omits specified properties from an object | | checkType | (val: unknown, type: string) | boolean | Checks the type of a value | | isUndefined | (val: unknown) | val is undefined | Checks if a value is undefined | | isNull | (val: unknown) | val is null | Checks if a value is null | | isNullOrUndefined | (val: unknown) | val is null | undefined | Checks if a value is null or undefined | | isNumber | (val: unknown) | val is number | Checks if a value is a number | | isString | (val: unknown) | val is string | Checks if a value is a string | | isBoolean | (val: unknown) | val is boolean | Checks if a value is a boolean | | isObject | (val: unknown) | val is Record | Checks if a value is an object | | isSymbol | (val: unknown) | val is symbol | Checks if a value is a symbol | | isSet | (val: unknown) | val is Set | Checks if a value is a set | | isWeakSet | (val: unknown) | val is WeakSet