Class representing a 4D [link:https://en.wikipedia.org/wiki/Vector_space vector]. A 4D vector is an ordered quadruplet of numbers (labeled x, y, z, and w), which can be used to represent a number of things, such as:

- A point in 4D space.
- A direction and length in 4D space. In three.js the length will always be the [link:https://en.wikipedia.org/wiki/Euclidean_distance Euclidean distance] (straight-line distance) from (0, 0, 0, 0) to (x, y, z, w) and the direction is also measured from (0, 0, 0, 0) towards (x, y, z, w).
- Any arbitrary ordered quadruplet of numbers.

There are other things a 4D vector can be used to represent, however these are the most common uses in three.js.

```
const a = new THREE.Vector4( 0, 1, 0, 0 );
//no arguments; will be initialised to (0, 0, 0, 1)
const b = new THREE.Vector4( );
const d = a.dot( b );
```

[page:Float x] - the x value of this vector. Default is *0*.

[page:Float y] - the y value of this vector. Default is *0*.

[page:Float z] - the z value of this vector. Default is *0*.

[page:Float w] - the w value of this vector. Default is *1*.

Creates a new [name].

Alias for [page:.z z].

Alias for [page:.w w].

Adds [page:Vector4 v] to this vector.

Adds the scalar value s to this vector's [page:.x x], [page:.y y], [page:.z z] and [page:.w w] values.

Adds the multiple of [page:Vector4 v] and [page:Float s] to this vector.

Sets this vector to [page:Vector4 a] + [page:Vector4 b].

Multiplies this vector by 4 x 4 [page:Matrix4 m].

The [page:.x x], [page:.y y], [page:.z z] and [page:.w w] components of this vector are rounded up to the nearest integer value.

[page:Vector4 min] - the minimum [page:.x x], [page:.y y], [page:.z z] and [page:.w w] values.

[page:Vector4 max] - the maximum [page:.x x], [page:.y y], [page:.z z] and [page:.w w] values in the desired range

If this vector's x, y, z or w value is greater than the max vector's x, y, z or w value, it is replaced by the corresponding value.

If this vector's x, y, z or w value is less than the min vector's x, y, z or w value, it is replaced by the corresponding value.

[page:Float min] - the minimum value the length will be clamped to

[page:Float max] - the maximum value the length will be clamped to

If this vector's length is greater than the max value, it is replaced by the max value.

If this vector's length is less than the min value, it is replaced by the min value.

[page:Float min] - the minimum value the components will be clamped to

[page:Float max] - the maximum value the components will be clamped to

If this vector's x, y, z or w values are greater than the max value, they are replaced by the max value.

If this vector's x, y, z or w values are less than the min value, they are replaced by the min value.

Returns a new Vector4 with the same [page:.x x], [page:.y y], [page:.z z] and [page:.w w] values as this one.

Copies the values of the passed Vector4's [page:.x x], [page:.y y], [page:.z z] and [page:.w w] properties to this Vector4.

Divides this vector by scalar [page:Float s].

Sets vector to *( 0, 0, 0, 0 )* if *[page:Float s] = 0*.

Calculates the [link:https://en.wikipedia.org/wiki/Dot_product dot product] of this vector and [page:Vector4 v].

Checks for strict equality of this vector and [page:Vector4 v].

The components of this vector are rounded down to the nearest integer value.

[page:Array array] - the source array.

[page:Integer offset] - (optional) offset into the array. Default is 0.

Sets this vector's [page:.x x] value to be array[ offset + 0 ], [page:.y y] value to be array[ offset + 1 ]
[page:.z z] value to be array[ offset + 2 ] and [page:.w w ] value to be array[ offset + 3 ].

[page:BufferAttribute attribute] - the source attribute.

[page:Integer index] - index in the attribute.

Sets this vector's [page:.x x], [page:.y y], [page:.z z] and [page:.w w] values from the [page:BufferAttribute attribute].

[page:Integer index] - 0, 1, 2 or 3.

If index equals 0 returns the [page:.x x] value.

If index equals 1 returns the [page:.y y] value.

If index equals 2 returns the [page:.z z] value.

If index equals 3 returns the [page:.w w] value.

Computes the [link:https://en.wikipedia.org/wiki/Euclidean_distance Euclidean length] (straight-line length) from (0, 0, 0, 0) to (x, y, z, w).

Computes the [link:http://en.wikipedia.org/wiki/Taxicab_geometry Manhattan length] of this vector.

Computes the square of the [link:https://en.wikipedia.org/wiki/Euclidean_distance Euclidean length] (straight-line length) from (0, 0, 0, 0) to (x, y, z, w). If you are comparing the lengths of vectors, you should compare the length squared instead as it is slightly more efficient to calculate.

[page:Vector4 v] - [page:Vector4] to interpolate towards.

[page:Float alpha] - interpolation factor, typically in the closed interval [0, 1].

Linearly interpolates between this vector and [page:Vector4 v], where alpha is the
percent distance along the line - alpha = 0 will be this vector, and alpha = 1 will be [page:Vector4 v].

[page:Vector4 v1] - the starting [page:Vector4].

[page:Vector4 v2] - [page:Vector4] to interpolate towards.

[page:Float alpha] - interpolation factor, typically in the closed interval [0, 1].

Sets this vector to be the vector linearly interpolated between [page:Vector4 v1] and
[page:Vector4 v2] where alpha is the percent distance along the line connecting the two vectors
- alpha = 0 will be [page:Vector4 v1], and alpha = 1 will be [page:Vector4 v2].

Inverts this vector - i.e. sets x = -x, y = -y, z = -z and w = -w.

Converts this vector to a [link:https://en.wikipedia.org/wiki/Unit_vector unit vector] - that is, sets it equal to a vector with the same direction as this one, but [page:.length length] 1.

If this vector's x, y, z or w value is less than [page:Vector4 v]'s x, y, z or w value, replace that value with the corresponding max value.

If this vector's x, y, z or w value is greater than [page:Vector4 v]'s x, y, z or w value, replace that value with the corresponding min value.

Multiplies this vector by [page:Vector4 v].

Multiplies this vector by scalar [page:Float s].

The components of this vector are rounded to the nearest integer value.

The components of this vector are rounded towards zero (up if negative, down if positive) to an integer value.

Sets the [page:.x x], [page:.y y], [page:.z z] and [page:.w w] components of this vector.

[page:Quaterion q] - a normalized [page:Quaterion]

Sets the [page:.x x], [page:.y y] and [page:.z z] components of this vector to the
quaternion's axis and [page:.w w] to the angle.

[page:Matrix4 m] - a [page:Matrix4] of which the upper left 3x3 matrix is a pure rotation matrix.

Sets the [page:.x x], [page:.y y] and [page:.z z] to the axis of rotation and [page:.w w] to the angle.

[page:Integer index] - 0, 1 or 2.

[page:Float value] - [page:Float]

If index equals 0 set [page:.x x] to [page:Float value].

If index equals 1 set [page:.y y] to [page:Float value].

If index equals 2 set [page:.z z] to [page:Float value].

If index equals 3 set [page:.w w] to [page:Float value].

Sets this vector to a vector with the same direction as this one, but [page:.length length] [page:Float l].

Sets the [page:.x x], [page:.y y], [page:.z z] and [page:.w w] values of this vector both equal to [page:Float scalar].

Replaces this vector's [page:.x x] value with [page:Float x].

Replaces this vector's [page:.y y] value with [page:Float y].

Replaces this vector's [page:.z z] value with [page:Float z].

Replaces this vector's [page:.w w] value with [page:Float w].

Subtracts [page:Vector4 v] from this vector.

Subtracts [page:Float s] from this vector's [page:.x x], [page:.y y], [page:.z z] and [page:.w w] compnents.

Sets this vector to [page:Vector4 a] - [page:Vector4 b].

[page:Array array] - (optional) array to store this vector to. If this is not provided, a new array will be created.

[page:Integer offset] - (optional) optional offset into the array.

Returns an array [x, y, z, w], or copies x, y, z and w into the provided [page:Array array].

Sets each component of this vector to a pseudo-random value between 0 and 1, excluding 1.

[link:https://github.com/mrdoob/three.js/blob/master/src/[path].js src/[path].js]