<section id="description">
  <p>Когда объявляются переменные JavaScript, они имеют начальное значение <code>undefined</code> . Если вы выполняете
    математическую операцию с <code>undefined</code> переменной, ваш результат будет <code>NaN</code> что означает
    <dfn>«Not a Number»</dfn> . Если вы конкатенируете строку с <code>undefined</code> переменной, вы получите буквенную
    <dfn>строку</dfn> <code>"undefined"</code> .</p>
</section>

// Initialize these three variables
var a;
var b;
var c;

// Do not change code below this line

a = a + 1;
b = b + 5;
c = c + " String!";


index

Понимание неинициализированных переменных

Understanding Uninitialized Variables

<code>a</code> should be defined and evaluated to have the value of <code>6</code>

<code>b</code> should be defined and evaluated to have the value of <code>15</code>

<code>c</code> should not contain <code>undefined</code> and should have a value of "I am a String!"

javascript-algorithms-and-data-structures

Basic JavaScript

// Initialize these three variables
var a = 5;
var b = 10;
var c = "I am a";

// Do not change code below this line

a = a + 1;
b = b + 5;
c = c + " String!";


// Initialize these three variables
var a=5;
var b=10;
var c="I am a";

// Do not change code below this line

a = a + 1;
b = b + 5;
c = c + " String!";


// Initialize these three variables
var a;
var b;
var c;

// Do not change code below this line

a = 5;
b = 10;
c = "I am a";
a = a + 1;
b = b + 5;
c = c + " String!";


// Initialize these three variables
var a = 5;
var b = 10;
var c = "I am a";

// Do not change code below this line

a = a + 1;
b = b + 5;
c = c + " String!";



// Initialize these three variables
var a =5;
var b =10;
var c = "I am a";

// Do not change code below this line

a = a + 1;
b = b + 5;
c = c + " String!";


// Initialize these three variables
var a;
var b;
var c;

// Do not change code below this line
a = 5;
b = 10;
c = "I am a"
a = a + 1;
b = b + 5;
c = c + " String!";


// Initialize these three variables
var a;
var b;
var c;
a = 5;
b = 10;
c = "I am a"

// Do not change code below this line

a = a + 1;
b = b + 5;
c = c + " String!";


// Initialize these three variables
var a;
var b;
var c;

// Do not change code below this line

a = a + 1;
b = b + 5;
c = c + " String!";
a = 6;
b = 15;
c = "I am a String!"

// Initialize these three variables
var a = 5;
var b = 10;
var c ='I am a';

// Do not change code below this line

a = a + 1;
b = b + 5;
c = c + " String!";


// Initialize these three variables
var a;
var b;
var c;
a=5;
b=10;
c="I am a"
// Do not change code below this line

a = a + 1;
b = b + 5;
c = c + " String!";


// Initialize these three variables
var a = 5;
var b = 10;
var c = 'I am a';

// Do not change code below this line

a = a + 1;
b = b + 5;
c = c + " String!";


// Initialize these three variables
var a = 5;
var b = 10;
var c = "I am a"  ;

// Do not change code below this line
a = a + 1;
b = b + 5;
c = c + " String!";


// Initialize these three variables
var a = 5;
var b = 10;
var c = "I am a";

// Do not change code below this line

a = a + 1;
b = b + 5;
c = c + " String!";




// Initialize these three variables
var a;
var b;
var c;

// Do not change code below this line
a = 5;
b = 10;
c = "I am a"

a = a + 1;
b = b + 5;
c = c + " String!";


// Initialize these three variables
var a=5;
var b=10;
var c='I am a';

// Do not change code below this line

a = a + 1;
b = b + 5;
c = c + " String!";


// Initialize these three variables
var a;
var b;
var c;

a = 5;
b=10;
c = "I am a"
// Do not change code below this line

a = a + 1;
b = b + 5;
c = c + " String!";


// Initialize these three variables
var a;
var b;
var c;

// Do not change code below this line


a = a + 1;
b = b + 5;
c = c + " String!";

a = 5 + 1;
b = 10 + 5;
c = "I am a" + " String!";


// Initialize these three variables
var a = 5;
var b =10;
var c ='I am a';

// Do not change code below this line

a = a + 1;
b = b + 5;
c = c + " String!";


// Initialize these three variables
var a;
var b;
var c;
var a = 5;
var b = 10;
var c  = "I am a";

// Do not change code below this line

a = a + 1;
b = b + 5;
c = c + " String!";


// Initialize these three variables
var a = 5;
var b = 10;
var c = "I am a";

// Do not change code below this line

a = a + 1;
b = b + 5;
c = c + " String!";

a = 6;
b = 15;
c = "I am a String!";

// Initialize these three variables
var a;
var b;
var c;

// Do not change code below this line
var a=5;
var b=10;
var c = "I am a";
a = a + 1;
b = b + 5;
c = c + " String!";


// Initialize these three variables
var a;
var b;
var c;

// Do not change code below this line

a = a + 1;
b = b + 5;
c = c + " String!";

var a = 6;
var b = 15;
var c = "I am a String!";

// Initialize these three variables
var a;
var b;
var c;
a = 5;
b = 10;
c = "I am a";

// Do not change code below this line

a = a + 1;
b = b + 5;
c = c + " String!";


// Initialize these three variables
var a;
var b;
var c;

// Do not change code below this line
a = 5;
b = 10;
c = "I am a";

a = a + 1;
b = b + 5;
c = c + " String!";



// Initialize these three variables
var a;
var b;
var c;
a = 5;
b = 10;
c = "I am a"
// Do not change code below this line

a = a + 1;
b = b + 5;
c = c + " String!";


// Initialize these three variables
var a;
var b;
var c;
a=5;
b=10;
c ='I am a'
// Do not change code below this line

a = a + 1;
b = b + 5;
c = c + " String!";


// Initialize these three variables
var a;
var b;
var c;
a=5;
b=10;
c="I am a"




// Do not change code below this line

a = a + 1;
b = b + 5;
c = c + " String!";


// Initialize these three variables
var a;
var b;
var c;

// Do not change code below this line
a=5;
b=10;
c='I am a';
a = a + 1;
b = b + 5;
c = c + " String!";


// Initialize these three variables
var a;
var b;
var c;

// Do not change code below this line
a = 5;
b = 10;
c = "I am a";
a = a + 1;
b = b + 5;
c = c + " String!";


// Initialize these three variables
var a=5;
var b=10;
var c ="I am a";

// Do not change code below this line

a = a + 1;
b = b + 5;
c = c + " String!";


// Initialize these three variables
var a;
var b;
var c;
a=5;
b=10;
c="I am a";
// Do not change code below this line

a = a + 1;
b = b + 5;
c = c + " String!";


// Initialize these three variables
var a;
var b;
var c;

// Do not change code below this line
var a = 5;
var b = 10;
var c = "I am a"
a = a + 1;
b = b + 5;
c = c + " String!";


// Initialize these three variables
var a;
var b;
var c;

// Do not change code below this line

a = a + 1;
b = b + 5;
c = c + " String!";


var a = 6;
var b = 15;
var c = "I am a String!";
var e = b + c;
alert (e);

// Initialize these three variables
var a = 5;
var b = 10;
var c = "I am a";



// Do not change code below this line

a = a + 1;
b = b + 5;
c = c + " String!";


// Initialize these three variables
var a = 5;
var b = 10;
var c = "I am a";

// Do not change code below this line

a = a + 1;
b = b + 5;
c = c + " String!";

// Initialize these three variables
var a;
var b;
var c;

// Do not change code below this line

a = 5;
b = 10;
c = "I am a";

a = a + 1;
b = b + 5;
c = c + " String!";



// Initialize these three variables
var a =5;
var b =10;
var c ="I am a";

// Do not change code below this line

a = a + 1;
b = b + 5;
c = c + " String!";


// Initialize these three variables
var a;
var b;
var c;

// Do not change code below this line

a = a + 1;
b = b + 5;
c = c + " String!";
var a = 6;
var b = 15;
var c = "I am a String!";

// Initialize these three variables
var a;
var b;
var c;


// Do not change code below this line
a = 5;
b = 10;
c = "I am a";
a = a + 1;
b = b + 5;
c = c + " String!";


// Initialize these three variables
var a;
var b;
var c;
a = 5;
b = 10;
c ="I am a"
// Do not change code below this line

a = a + 1;
b = b + 5;
c = c + " String!";


// Initialize these three variables
var a = 5;
var b = 10;
var c = "I am a";

// Do not change code below this line

a = a + 1;
b = b + 5;
c = c + " String!";
console.log(c)


// Initialize these three variables
var a;
var b;
var c;

// Do not change code below this line

a = 5;
b = 10;
c = "I am a";

a = a + 1;
b = b + 5;
c = c + " String!";


// Initialize these three variables
var a;
var b;
var c;
a = 5;
b = 10;
c = "I am a";
// Do not change code below this line

a = a + 1;
b = b + 5;
c = c + " String!";


// Initialize these three variables
var a;
var b;
var c;

a = 5;
b = 10;
c = "I am a";

// Do not change code below this line

a = a + 1;
b = b + 5;
c = c + " String!";


// Initialize these three variables
var a;
var a = 5;
var b;
var b = 10;
var c;
var c = "I am a"

// Do not change code below this line

a = a + 1;
b = b + 5;
c = c + " String!";


// Initialize these three variables
var a;
var b;
var c;


var a = 5;
var b = 10;
var c = "I am a";



//var ourVar = 19;
//var ourVar = a;
//var a = 9;


// Do not change code below this line

a = a + 1;
b = b + 5;
c = c + " String!";


// Initialize these three variables
// var a;
// var b;
// var c;

// Do not change code below this line

var a = 5;
var b = 10 ;
var c = 'I am a';
a = a + 1;
b = b + 5;
c = c + " String!";


// Initialize these three variables
var a = 5;
var b= 10;
var c= "I am a";

// Do not change code below this line

a = a + 1;
b = b + 5;
c = c + " String!";


// Initialize these three variables
var a;
var b;
var c;

// Do not change code below this line

a = a + 1;
b = b + 5;
c = c + " String!";


a = 5 + 1;
b = 15;
c = "I am a" + " String!";

// Initialize these three variables
var a = 5;
var b = 10;
var c = "I am a";

// Do not change code below this line

a = a + 1;
b = b + 5;
c = c + " String!";
console.log("a");

// Setup
var a = 5;
var b = 10;
var c = 'I am a';

// Only change code below this line

a = a + 1;
b = b + 5;
c = c + " String!";


// Initialize these three variables
var a;
var b;
var c;

// Do not change code below this line

a = a + 1;
b = b + 5;
c = c + " String!";
a = 6;
b = 15;
c = "I am a String!";

// Initialize these three variables
var a = 5;
var b = 10;
var c= "I am a";

// Do not change code below this line

a = a + 1;
b = b + 5;
c = c + " String!";


// Initialize these three variables
var a;
var b;
var c;

// Do not change code below this line

a = a + 1;
b = b + 5;
c = c + " String!";
var a = 5;
var b = 10;
var c = "I am a"
a = a + 1;
b = b + 5;
c = c + " String!";

// Initialize these three variables
var a;
var b;
var c;

a = 5;
b = 10;
c = "I am a";
// Do not change code below this line

a = a + 1;
b = b + 5;
c = c + " String!";


// Initialize these three variables
var a;
var b;
var c;

// Do not change code below this line
var a = 5;
var b = 10;
var c = "I am a";

a = a + 1;
b = b + 5;
c = c + " String!";



// Initialize these three variables
var a = 5;
var b = 10;
var c = 'I am a';

// Do not change code below this line

a = a + 1;
b = b + 5;
c = c + " String!";



// Initialize these three variables
var a=5;
var b=10;
var c = 'I am a';

// Do not change code below this line

a = a + 1;
b = b + 5;
c = c + " String!";


// Initialize these three variables
var a=5;
var b = 10;
var c = "I am a";

// Do not change code below this line

a = a + 1;
b = b + 5;
c = c + " String!";


// Initialize these three variables
var a = 5;
var b = 10;
var c = "I am a";

// Do not change code below this line

a = a + 1;
b = b + 5;
c = c + " String!";
console.log(a, b, c)

// Initialize these three variables
var a=5;
var b=10;
var c="I am a";

// Do not change code below this line

a = a + 1;
b = b + 5;
c = c + " String!";

// Initialize these three variables
var a;
var b;
var c;

// Do not change code below this line
var a = 5;
var b = 10;
var c = "I am a"
a = a + 1;
b = b + 5;
c = c + " String!";

// Initialize these three variables
var a= 5;
var b= 10;
var c= "I am a";

// Do not change code below this line

a = a + 1;
b = b + 5;
c = c + " String!";


RichText

Артемий, вы правы, здесь есть путаница. Дело в том, что в описании указаны требования к инициализируемым переменным, а в тестах проверка уже конечных значений (после переопределения значений переменных). Дополнил описание. Так должно стать понятней.

Уроки

В описании задания одни требоваиня, а в тестах - другие.

FreeCode.Academy

Обсуждение задания "Understanding Uninitialized Variables"

Добавить комментарий