{
 "cells": [
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   "cell_type": "markdown",
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   "source": [
    "## Notebook 3"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## For loops\n"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Write a `for loop` that prints each item in the list `['python','perl','java','C++']`\n",
    "\n",
    "Now modify your code so that it prints only the second character in each item (so: `y, e, a, +`)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## While loops"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Write a `while loop` that prints each item in the list `['python','perl','java','C++']`\n",
    "\n",
    "Modify your script so that it prints each item in the list + which position it has in the list:  \n",
    "`python has position 0 in the list`  \n",
    "`perl has position 1 in the list`  \n",
    "`java has position 2 in the list`  \n",
    "`C++ has position 3 in the list`  "
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### Answers\n",
    "\n",
    "### For loops"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 1,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "python\n",
      "perl\n",
      "java\n",
      "C++\n"
     ]
    }
   ],
   "source": [
    "languages = ['python','perl','java','C++']   # Save all languages to a list\n",
    "for language in languages:                   # Use a foor loop to go to each item in turn in the list and do something...\n",
    "    print(language)                          # In this case printing the output"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "y\n",
      "e\n",
      "a\n",
      "+\n"
     ]
    }
   ],
   "source": [
    "languages = ['python','perl','java','C++']\n",
    "for language in languages: \n",
    "    print(language[1])                      # language is an iterable item in fruits, so you can use index to access characters"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### While loops"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "python\n",
      "perl\n",
      "java\n",
      "C++\n"
     ]
    }
   ],
   "source": [
    "languages = ['python','perl','java','C++']     # Save all languages to a list\n",
    "i = 0                                          # Set a counter on where to start in the list (0)\n",
    "while i < len(languages):                      # Run loop as long as this statement is true. \n",
    "    print(languages[i])                        # Use i for index of languages\n",
    "    i = i + 1                                  # Don't forget to increase i with 1, otherwise you have an infinite loop"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "python has position 0 in the list\n",
      "perl has position 1 in the list\n",
      "java has position 2 in the list\n",
      "C++ has position 3 in the list\n"
     ]
    }
   ],
   "source": [
    "languages = ['python','perl','java','C++']\n",
    "i = 0                                          \n",
    "while i < len(languages):                         \n",
    "    print(languages[i]+' has position '+str(i)+' in the list')  # Use the counter i to print the position\n",
    "    i = i + 1                                  "
   ]
  }
 ],
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