# CellValue
```csharp
public readonly struct CellValue
```
Namespace `SharpCell` ยท package `SharpCell`
A value produced by a cell or a formula. `default` is [CellValue.Empty](SharpCell.CellValue.md#empty). Equality is identity (same kind, same payload, ordinal text), not Excel's `=`.
## Properties
### Empty
```csharp
public static CellValue Empty { get; }
```
An empty cell.
### False
```csharp
public static CellValue False { get; }
```
The logical value FALSE.
### IsError
```csharp
public bool IsError { get; }
```
Whether the value is an Excel error.
### Kind
```csharp
public CellValueKind Kind { get; }
```
The kind of value; check it before calling one of the `As` methods.
### Missing
```csharp
public static CellValue Missing { get; }
```
An omitted function argument, as in `IF(A1,,B1)`.
### True
```csharp
public static CellValue True { get; }
```
The logical value TRUE.
## Methods
### Array(CellValue[,])
```csharp
public static CellValue Array(CellValue[,] values)
```
A rectangular array. The array is taken by reference and must not be mutated afterwards. Excel has no empty arrays, so both dimensions must be at least 1.
### AsArray()
```csharp
public CellValue[,] AsArray()
```
The array, rows first. Throws `InvalidOperationException` when [CellValue.Kind](SharpCell.CellValue.md#kind) is not [CellValueKind.Array](SharpCell.CellValueKind.md#array).
### AsBoolean()
```csharp
public bool AsBoolean()
```
The logical value. Throws `InvalidOperationException` when [CellValue.Kind](SharpCell.CellValue.md#kind) is not [CellValueKind.Boolean](SharpCell.CellValueKind.md#boolean).
### AsDateTime(DateSystem)
```csharp
public DateTime AsDateTime(DateSystem system)
```
The number read as a date and time: Excel stores dates as serial days counted from the workbook's `system` ([Workbook.DateSystem](SharpCell.Workbook.md#datesystem)), the time of day as the fraction, here rounded to the millisecond. The result's kind is `DateTimeKind.Unspecified`, as Excel knows no time zones.
**Exceptions**
- `InvalidOperationException`: [CellValue.Kind](SharpCell.CellValue.md#kind) is not [CellValueKind.Number](SharpCell.CellValueKind.md#number).
- `ArgumentOutOfRangeException`: The number is no date: negative, past 9999-12-31, or 60 in the 1900 system, which Excel shows as the non-existent 1900-02-29.
### AsError()
```csharp
public ErrorKind AsError()
```
The error. Throws `InvalidOperationException` when [CellValue.Kind](SharpCell.CellValue.md#kind) is not [CellValueKind.Error](SharpCell.CellValueKind.md#error).
### AsLambda()
```csharp
public LambdaValue AsLambda()
```
The function value. Throws `InvalidOperationException` when [CellValue.Kind](SharpCell.CellValue.md#kind) is not [CellValueKind.Lambda](SharpCell.CellValueKind.md#lambda).
### AsNumber()
```csharp
public double AsNumber()
```
The number. Throws `InvalidOperationException` when [CellValue.Kind](SharpCell.CellValue.md#kind) is not [CellValueKind.Number](SharpCell.CellValueKind.md#number).
### AsText()
```csharp
public string AsText()
```
The text. Throws `InvalidOperationException` when [CellValue.Kind](SharpCell.CellValue.md#kind) is not [CellValueKind.Text](SharpCell.CellValueKind.md#text).
### Boolean(bool)
```csharp
public static CellValue Boolean(bool value)
```
A logical value.
### DateTime(DateTime, DateSystem)
```csharp
public static CellValue DateTime(DateTime value, DateSystem system)
```
A date and time as the serial number Excel stores: days counted from the workbook's `system` ([Workbook.DateSystem](SharpCell.Workbook.md#datesystem)), the time of day as the fraction.
**Exceptions**
- `ArgumentOutOfRangeException`: The date is before the date system starts: 1899-12-31 in the 1900 system, 1904-01-01 in the 1904 system.
### Equals(CellValue)
```csharp
public bool Equals(CellValue other)
```
Whether both values have the same kind and content; arrays are compared element by element. This is not Excel's `=`, which ignores case.
### Equals(object)
```csharp
public override bool Equals(object? obj)
```
Whether `obj` is a [CellValue](SharpCell.CellValue.md) equal to this one.
### Error(ErrorKind)
```csharp
public static CellValue Error(ErrorKind kind)
```
An error value.
### GetHashCode()
```csharp
public override int GetHashCode()
```
A hash code consistent with [CellValue.Equals](SharpCell.CellValue.md#equals-cellvalue).
### Lambda(LambdaValue)
```csharp
public static CellValue Lambda(LambdaValue value)
```
A function value.
### Number(double)
```csharp
public static CellValue Number(double value)
```
A number. Excel has neither NaN, infinities nor negative zero: non-finite input becomes `#NUM!` and `-0` becomes `0`.
### Text(string)
```csharp
public static CellValue Text(string value)
```
A text value.
### ToString()
```csharp
public override string ToString()
```
Formats the value the way it would be written as a formula literal.
## Operators
### implicit operator CellValue(bool)
```csharp
public static implicit operator CellValue(bool value)
```
A logical value, so `cell.Value = true` works.
### implicit operator CellValue(double)
```csharp
public static implicit operator CellValue(double value)
```
A number, so `cell.Value = 42` works.
### implicit operator CellValue(string)
```csharp
public static implicit operator CellValue(string value)
```
A text value, so `cell.Value = "text"` works.
### operator !=(CellValue, CellValue)
```csharp
public static bool operator !=(CellValue left, CellValue right)
```
Whether the values differ, as [CellValue.Equals](SharpCell.CellValue.md#equals-cellvalue).
### operator ==(CellValue, CellValue)
```csharp
public static bool operator ==(CellValue left, CellValue right)
```
Whether the values are equal, as [CellValue.Equals](SharpCell.CellValue.md#equals-cellvalue).