# FormulaSyntaxTree ## Content

Class FormulaSyntaxTree

java.lang.Object
com.grapecity.documents.excel.expressions.FormulaSyntaxTree
All Implemented Interfaces:
Cloneable
public class FormulaSyntaxTree extends Object implements Cloneable
Represents a formula as a syntax tree.

This class is the entry point for the formula expression API. A FormulaSyntaxTree can be created as an empty tree and then populated by assigning a root SyntaxNode, or it can be created from formula text by using Parse(String). After the tree is built, you can inspect its structure with getRoot() or convert it back to formula text with toString().


 String formula = "LET(AppUpTime,NOW()-DATE(2020,4,17)+366, YEAR(AppUpTime)-1900-1 & \" years\")";
 FormulaSyntaxTree syntaxTree = FormulaSyntaxTree.Parse(formula);
 FunctionNode find = new FunctionNode("NOW");
 FunctionNode replacement = new FunctionNode("DATE");
 replacement.getChildren().add(new NumberNode(2021));
 replacement.getChildren().add(new NumberNode(2));
 replacement.getChildren().add(new NumberNode(14));

 java.util.Stack<SyntaxNode> nodes = new java.util.Stack<SyntaxNode>();
 nodes.push(syntaxTree.getRoot());
 while (!nodes.isEmpty()) {
     java.util.List<SyntaxNode> children = nodes.pop().getChildren();
     for (int i = 0; i < children.size(); i++) {
         SyntaxNode child = children.get(i);
         if (child.equals(find)) {
             children.set(i, replacement);
         } else {
             nodes.push(child);
         }
     }
 }
 String formulaText = syntaxTree.toString();