text: 'use strict'
  
  /*
   * Create a `getFirst` function that takes an array or a string
   * and return the first element
   *
   * @notions Data-Structures, Get
   */
  
  // Your code :
  const getFirst = (x) => {
      if(typeof x == 'string')
          return(x.substring(0,1));
      if(Array.isArray(x))
          return(x.shift());
  }
  //* Begin of tests
  const assert = require('assert')
  console.log(getFirst("Hello"))
  console.log(getFirst([1,2,3]))
  assert.strictEqual(getFirst([ 2, 42 ]), 2)
  assert.strictEqual(getFirst([ 'pouet', 4, true ]), 'pouet')
  assert.strictEqual(getFirst([ getFirst ]), getFirst)
  assert.strictEqual(getFirst('salut'), 's')
  assert.strictEqual(getFirst([]), undefined)
  // End of tests */
  