## FieldIf class

Implements the IF field.

To learn more, visit the [Working with Fields](https://docs.aspose.com/words/net/working-with-fields/) documentation article.

```csharp
public class FieldIf : Field
```

## Constructors

| Name | Description |
| --- | --- |
| [FieldIf](fieldif/)() | The default constructor. |

## Properties

| Name | Description |
| --- | --- |
| [ComparisonOperator](../../aspose.words.fields/fieldif/comparisonoperator/) { get; set; } | Gets or sets the comparison operator. |
| [DisplayResult](../../aspose.words.fields/field/displayresult/) { get; } | Gets the text that represents the displayed field result. |
| [End](../../aspose.words.fields/field/end/) { get; } | Gets the node that represents the field end. |
| [FalseText](../../aspose.words.fields/fieldif/falsetext/) { get; set; } | Gets or sets the text displayed if the comparison expression is `false`. |
| [Format](../../aspose.words.fields/field/format/) { get; } | Gets a [`FieldFormat`](../fieldformat/) object that provides typed access to field's formatting. |
| [IsDirty](../../aspose.words.fields/field/isdirty/) { get; set; } | Gets or sets whether the current result of the field is no longer correct (stale) due to other modifications made to the document. |
| [IsLocked](../../aspose.words.fields/field/islocked/) { get; set; } | Gets or sets whether the field is locked (should not recalculate its result). |
| [LeftExpression](../../aspose.words.fields/fieldif/leftexpression/) { get; set; } | Gets or sets the left part of the comparison expression. |
| [LocaleId](../../aspose.words.fields/field/localeid/) { get; set; } | Gets or sets the LCID of the field. |
| [Result](../../aspose.words.fields/field/result/) { get; set; } | Gets or sets text that is between the field separator and field end. |
| [RightExpression](../../aspose.words.fields/fieldif/rightexpression/) { get; set; } | Gets or sets the right part of the comparison expression. |
| [Separator](../../aspose.words.fields/field/separator/) { get; } | Gets the node that represents the field separator. Can be `null`. |
| [Start](../../aspose.words.fields/field/start/) { get; } | Gets the node that represents the start of the field. |
| [TrueText](../../aspose.words.fields/fieldif/truetext/) { get; set; } | Gets or sets the text displayed if the comparison expression is true. |
| virtual [Type](../../aspose.words.fields/field/type/) { get; } | Gets the Microsoft Word field type. |

## Methods

| Name | Description |
| --- | --- |
| [EvaluateCondition](../../aspose.words.fields/fieldif/evaluatecondition/)() | Evaluates the condition. |
| [GetFieldCode](../../aspose.words.fields/field/getfieldcode/)() | Returns text between field start and field separator (or field end if there is no separator). Both field code and field result of child fields are included. |
| [GetFieldCode](../../aspose.words.fields/field/getfieldcode/)(*bool*) | Returns text between field start and field separator (or field end if there is no separator). |
| virtual [Remove](../../aspose.words.fields/field/remove/)() | Removes the field from the document. Returns a node right after the field. If the field's end is the last child of its parent node, returns its parent paragraph. If the field is already removed, returns `null`. |
| [Unlink](../../aspose.words.fields/field/unlink/)() | Performs the field unlink. |
| [Update](../../aspose.words.fields/field/update/)() | Performs the field update. Throws if the field is being updated already. |
| [Update](../../aspose.words.fields/field/update/)(*bool*) | Performs a field update. Throws if the field is being updated already. |

## Remarks

Compares the values designated by the expressions [`LeftExpression`](./leftexpression/) and [`RightExpression`](./rightexpression/) in comparison using the operator designated by [`ComparisonOperator`](./comparisonoperator/).

A field in the following format will be used as a mail merge source: { IF 0 = 0 "{PatientsNameFML}" "" \* MERGEFORMAT }

## Examples

Shows how to insert an IF field.

```csharp
Document doc = new Document();
DocumentBuilder builder = new DocumentBuilder(doc);

builder.Write("Statement 1: ");
FieldIf field = (FieldIf)builder.InsertField(FieldType.FieldIf, true);
field.LeftExpression = "0";
field.ComparisonOperator = "=";
field.RightExpression = "1";

// The IF field will display a string from either its "TrueText" property,
// or its "FalseText" property, depending on the truth of the statement that we have constructed.
field.TrueText = "True";
field.FalseText = "False";
field.Update();

// In this case, "0 = 1" is incorrect, so the displayed result will be "False".
Assert.That(field.GetFieldCode(), Is.EqualTo(" IF  0 = 1 True False"));
Assert.That(field.EvaluateCondition(), Is.EqualTo(FieldIfComparisonResult.False));
Assert.That(field.Result, Is.EqualTo("False"));

builder.Write("\nStatement 2: ");
field = (FieldIf)builder.InsertField(FieldType.FieldIf, true);
field.LeftExpression = "5";
field.ComparisonOperator = "=";
field.RightExpression = "2 + 3";
field.TrueText = "True";
field.FalseText = "False";
field.Update();

// This time the statement is correct, so the displayed result will be "True".
Assert.That(field.GetFieldCode(), Is.EqualTo(" IF  5 = \"2 + 3\" True False"));
Assert.That(field.EvaluateCondition(), Is.EqualTo(FieldIfComparisonResult.True));
Assert.That(field.Result, Is.EqualTo("True"));

doc.UpdateFields();
doc.Save(ArtifactsDir + "Field.IF.docx");
```

### See Also

* class [Field](../field/)
* namespace [Aspose.Words.Fields](../../aspose.words.fields/)
* assembly [Aspose.Words](../../)