# Function parse Parse an expression. Returns a node tree, which can be evaluated by invoking node.evaluate(). Note the evaluating arbitrary expressions may involve security risks, see [https://mathjs.org/docs/expressions/security.html](https://mathjs.org/docs/expressions/security.html) for more information. ## Syntax ```js math.parse(expr) math.parse(expr, options) math.parse([expr1, expr2, expr3, ...]) math.parse([expr1, expr2, expr3, ...], options) ``` ### Parameters Parameter | Type | Description --------- | ---- | ----------- `expr` | string | string[] | Matrix | Expression to be parsed `options` | {nodes: Object<string, Node>} | Available options:
- `nodes` a set of custom nodes ### Returns Type | Description ---- | ----------- Node | Node[] | node ## Examples ```js const node1 = math.parse('sqrt(3^2 + 4^2)') node1.compile().evaluate() // 5 let scope = {a:3, b:4} const node2 = math.parse('a * b') // 12 const code2 = node2.compile() code2.evaluate(scope) // 12 scope.a = 5 code2.evaluate(scope) // 20 const nodes = math.parse(['a = 3', 'b = 4', 'a * b']) nodes[2].compile().evaluate() // 12 ``` ## See also [evaluate](evaluate.md), [compile](compile.md)