using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class PlayerMovement : MonoBehaviour
{
    public float speed;
    private float moveH;
    private Rigidbody2D rb2d;
    private Animator animator;
    private SpriteRenderer spriteRenderer;

    // ★追加（ジャンプ）
    public float jumpSpeed;
    public AudioClip jumpSound;

    void Start()
    {
        rb2d = GetComponent<Rigidbody2D>();
        animator = GetComponent<Animator>();
        spriteRenderer = GetComponent<SpriteRenderer>();
    }

    void Update()
    {
        moveH = Input.GetAxisRaw("Horizontal");
        rb2d.velocity = new Vector2(moveH * speed, rb2d.velocity.y);

        animator.SetFloat("Speed", moveH);

        if (moveH > 0.5f)
        {
            spriteRenderer.flipX = false;
        }
        else if (moveH < -0.5f)
        {
            spriteRenderer.flipX = true;
        }

        // ★追加（ジャンプ）
        if (Input.GetKeyDown(KeyCode.Space))
        {
            rb2d.velocity = Vector2.up * jumpSpeed;
            AudioSource.PlayClipAtPoint(jumpSound, Camera.main.transform.position);
        }
    }
}
C#

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class PlayerMovement : MonoBehaviour
{
    public float speed;
    private float moveH;
    private Rigidbody2D rb2d;
    private Animator animator;
    private SpriteRenderer spriteRenderer;
    public float jumpSpeed;
    public AudioClip jumpSound;

    // ★追加（二段ジャンプの禁止）
    public LayerMask floor;

    void Start()
    {
        rb2d = GetComponent<Rigidbody2D>();
        animator = GetComponent<Animator>();
        spriteRenderer = GetComponent<SpriteRenderer>();
    }

    void Update()
    {
        moveH = Input.GetAxisRaw("Horizontal");
        rb2d.velocity = new Vector2(moveH * speed, rb2d.velocity.y);

        animator.SetFloat("Speed", moveH);

        if (moveH > 0.5f)
        {
            spriteRenderer.flipX = false;
        }
        else if (moveH < -0.5f)
        {
            spriteRenderer.flipX = true;
        }

        if (Input.GetKeyDown(KeyCode.Space) && IsGrounded()) // ★追加（二段ジャンプの禁止）
        {
            rb2d.velocity = Vector2.up * jumpSpeed;
            AudioSource.PlayClipAtPoint(jumpSound, Camera.main.transform.position);
        }
    }

    // ★追加（二段ジャンプの禁止）
    // 接地判定のメソッド
    private bool IsGrounded()
    {
        RaycastHit2D hit2d = Physics2D.Raycast(transform.position, Vector2.down, 0.6f, floor);
        return hit2d.collider != null;
    }
}
C#