2-1-2_procedure_and_function.ipynb

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    "## 2-1-2 手続と関数\n",
    "手続も関数も，一連の処理の流れをまとめて記述したものです。Pythonでは，すべて関数として定義します。\n",
    "\n",
    "### 代入文手続と関数の利用目的\n",
    "【例】三角形の面積を計算する関数triangleArea"
   ]
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   "source": [
    "def triangleArea(base : float, height : float) -> float:\n",
    "    area = base * height / 2\n",
    "    return area"
   ]
  },
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   "source": [
    "【例】関数triangleAreaの実行"
   ]
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     "text": [
      "7.5\n"
     ]
    }
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   "source": [
    "area = triangleArea(5.0, 3.0)\n",
    "print(area)"
   ]
  },
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   "source": [
    "【例】文字列のリストを数値に変換して合計する関数sumArray  \n",
    "※Pythonでは，isDigit関数については，変数の型を判定するメソッドisdigit()として用意されています。intは，あらかじめ組み込み関数として用意されています。"
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    "def sumArray(digitArray : str) -> int:\n",
    "    sumDigit : int = 0\n",
    "    for i in range(len(digitArray)):\n",
    "        if (digitArray[i].isdigit() == True):\n",
    "            sumDigit = sumDigit + int(digitArray[i])\n",
    "    return sumDigit"
   ]
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   "source": [
    "【例】関数sumArray(digitArray)の実行"
   ]
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   "execution_count": 4,
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   "outputs": [
    {
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     "text": [
      "5\n"
     ]
    }
   ],
   "source": [
    "digitArray : list = [\"1\", \"4\", \"a\"]\n",
    "gSumDigit : int = sumArray(digitArray)\n",
    "print(gSumDigit)"
   ]
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   "source": [
    "【例】大域変数 gVal  \n",
    "Pythonでは，大域変数の定義は不要です。しかし，関数内で大域変数を使用するときには，global 宣言が必要となります。"
   ]
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   "source": [
    "gVal : int = 0\n",
    "\n",
    "def countUp(n: int):\n",
    "    global gVal\n",
    "    lVal : int = n\n",
    "    print(lVal)\n",
    "    gVal = gVal + n"
   ]
  },
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   "source": [
    "【例】大域変数gValを使用する手続を実行"
   ]
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   "execution_count": 6,
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   "outputs": [
    {
     "name": "stdout",
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     "text": [
      "1\n",
      "2\n",
      "3\n",
      "6\n"
     ]
    }
   ],
   "source": [
    "countUp(1)\n",
    "countUp(2)\n",
    "countUp(3)\n",
    "print(gVal)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": []
  }
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