Vector2 / Vector3 Operations

using UnityEngine;

// Create a Vector2 (2D).
Vector2 v2 = new Vector2(float x, float y);

// Create a Vector3 (3D).
Vector3 v3 = new Vector3(float x, float y, float z);

// Returns the distance between two points.
float distance = Vector3.Distance(Vector3 a, Vector3 b);

// Normalizes a vector (returns a vector with a length of 1).
Vector3 normalized = Vector3.Normalize(Vector3 value);
Vector3 normalized = v3.normalized; // Also available as a property.

// Interpolates from a to b by t (0 to 1).
Vector3 interpolated = Vector3.Lerp(Vector3 a, Vector3 b, float t);

// Returns the length (magnitude) of a vector.
float length = v3.magnitude;

using UnityEngine;

public class VectorSample : MonoBehaviour
{
    [SerializeField] private Transform target;
    [SerializeField] private float moveSpeed = 3f;
    [SerializeField] private float attackRange = 5f;

    void Start()
    {
        // Basic Vector3 operations.
        Vector3 posA = new Vector3(0f, 0f, 0f);
        Vector3 posB = new Vector3(3f, 4f, 0f);

        // Calculate the distance between two points.
        float distance = Vector3.Distance(posA, posB);
        Debug.Log($"Distance: {distance}"); // 5

        // Get the magnitude of a vector.
        Vector3 moveDir = posB - posA;
        Debug.Log($"magnitude: {moveDir.magnitude}"); // 5

        // Normalize (convert to length 1).
        Vector3 unitVector = moveDir.normalized;
        Debug.Log($"normalized: {unitVector}"); // (0.6, 0.8, 0.0)

        // Use the dot product to check if the target is in front.
        Vector3 myForward = transform.forward;
        Vector3 toTarget = (target.position - transform.position).normalized;
        float dot = Vector3.Dot(myForward, toTarget);
        bool isInFront = dot > 0f;
        Debug.Log($"Target is in front: {isInFront}");
    }

    void Update()
    {
        if (target == null) return;

        // Check if the target is within attack range using sqrMagnitude for efficiency.
        Vector3 diff = target.position - transform.position;
        if (diff.sqrMagnitude < attackRange * attackRange)
        {
            Debug.Log("Target is within attack range!");
        }

        // Smoothly move toward the target using Vector3.Lerp().
        transform.position = Vector3.Lerp(
            transform.position,
            target.position,
            moveSpeed * Time.deltaTime
        );
    }
}

When comparing distances (e.g., "is the target within 5 meters?"), comparing sqrMagnitude against the squared distance is faster than using Distance(). magnitude performs a square root calculation (Sqrt) internally, so calling it every frame inside Update() can add unnecessary overhead.

Vector2 and Vector3 can be implicitly converted to each other (the z component is treated as 0). For Unity's math functions in general, see Mathf. For time-based animations, consider using Coroutine / IEnumerator.