WebAssembly.Table.prototype.grow() - WebAssembly | MDN

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WebAssembly.Table.prototype.grow()

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since October 2017.

The grow() prototype method of the WebAssembly.Table object increases the size of the Table instance by a specified number of elements, filled with the provided value.

Syntax

js
grow(delta)
grow(delta, value)

Parameters

delta

The number of elements you want to grow the table by.

value Optional

The element to fill the newly-allocated space with.

Return value

The previous length of the table.

Exceptions

RangeError

Thrown in one of the following cases:

If the current size added with delta exceeds the Table instance's maximum size capacity.
If the client doesn't have enough memory for the allocation.

TypeError

Thrown if value is not a value of the element type of the table.

Examples

Using grow

The following example creates a new WebAssembly Table instance with an initial size of 2 and a maximum size of 10:

js
const table = new WebAssembly.Table({
  element: "anyfunc",
  initial: 2,
  maximum: 10,
});

Grow the table by 1 element using Table.grow():

js
console.log(table.length); // 2
table.grow(1);
console.log(table.length); // 3

Using grow with a value

The following example creates a new WebAssembly Table instance with an initial size of 0 and a maximum size of 4, filling it with an object:

js
const myObject = { hello: "world" };

const table = new WebAssembly.Table({
  element: "externref",
  initial: 0,
  maximum: 4,
});

Grow the table by 4 units and fill it with a value using WebAssembly.grow():

js
table.grow(4, myObject);
console.log(myObject === table.get(2)); // true

Specifications

Specification

WebAssembly JavaScript Interface
# dom-table-grow

Browser compatibility

Enable JavaScript to view this browser compatibility table.

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This page was last modified on Apr 22, 2025 by MDN contributors.

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