# GC.Spread.CalcEngine.Expression

## Content

# Class: Expression

[Spread](../modules/GC.Spread).[CalcEngine](../modules/GC.Spread.CalcEngine).Expression

## Table of contents

### Constructors

- [constructor](GC.Spread.CalcEngine.Expression#constructor)

### Properties

- [type](GC.Spread.CalcEngine.Expression#type)

## Constructors

### <a id="constructor" name="constructor"></a> constructor

• **new Expression**(`type`)

Provides the base class from which the classes that represent expression tree nodes are derived. This is an abstract class.

**`example`**
```javascript
// the below code will return a Expression
GC.Spread.Sheets.CalcEngine.formulaToExpression(sheet, "=1");
// Convert a formula string to an expression tree
const expression = GC.Spread.Sheets.CalcEngine.formulaToExpression(sheet, "=SUM(A1:B2)");
console.log(expression.type); // Returns ExpressionType.function
console.log(expression.functionName); // Returns "SUM"
```

#### Parameters

| Name | Type |
| :------ | :------ |
| `type` | [`ExpressionType`](../enums/GC.Spread.CalcEngine.ExpressionType) |

## Properties

### <a id="type" name="type"></a> type

• **type**: [`ExpressionType`](../enums/GC.Spread.CalcEngine.ExpressionType)

Indicates the type of expression node in the formula parse tree. Each expression node represents a specific element in a formula, such as a number, string, reference, function, or operator.

**`example`**
```javascript
console.log(GC.Spread.Sheets.CalcEngine.formulaToExpression(sheet, "=1").type === GC.Spread.CalcEngine.ExpressionType.number);
```