# JavaScript: Problems added in February 2016

complexity: **3** ; importance: **5**; author: **docentmail**

**Question:**What is percentage of support ECMAScript 5 in modern browsers?

complexity: **3** ; importance: **5**; author: **docentmail**

**Question:**What is percentage of support ECMAScript 6.0 in modern browsers?

complexity: **4** ; importance: **5**; author: **docentmail**

**Question:**Why standard for JavaScript has name ECMAScript?

complexity: **2** ; importance: **6**; author: **docentmail**

**Question:**What is the latest standard of ECMA script?

complexity: **4** ; importance: **5**; author: **docentmail**

**Question:**Which version of ECMA script is supported by current browsers?

complexity: **2** ; importance: **4**; author: **docentmail**

**Question:**What is the name of organization that maintains JavaScript standards?

complexity: **2** ; importance: **3**; author: **docentmail**

**Question:**What is the generic name of the values which evaluates to **false**?

complexity: **2** ; importance: **3**; author: **docentmail**

**Question:**What is the generic name of the values which evaluates to **true**?

complexity: **2** ; importance: **5**; author: **docentmail**

**Question:**Give definition for "truthy/falsy values" with **if** statement.

complexity: **4** ; importance: **5**; author: **docentmail**

**Question:**List all **falsy** values.

complexity: **6** ; importance: **2**; author: **docentmail**

**Question:** Why do you get the error **Fix errors in you script: TypeError: a is not a function** for the snippet?

var a=1 var b=a (function() { alert('hello'); })();

complexity: **2** ; importance: **24**; author: **docentmail**

**Question:** What would be result of execution of the snippet?

var x=1, y=1; x -- y alert(x); alert(y);

complexity: **2** ; importance: **24**; author: **docentmail**

**Question:** What is **typeof null;**?

alert(typeof null);

complexity: **2** ; importance: **2**; author: **docentmail**

**Question:** What would be message of the alert?

function fun(aaa /* some comments */ ){ // this is another comment return 'hello'; } alert (fun);

complexity: **5** ; importance: **2**; author: **docentmail**

**Question:** Give values for variables **a** and **b** to force first alert print **true** and second prints **false**.

var a=?; var b=?; alert(' a == b ' + (a == b) ); alert(' a===b '+ (a === b) );

complexity: **5** ; importance: **2**; author: **docentmail**

**Question:** What is the name of the practice and what is the purpose of starting libraries with **";"**?

;(function () {.......

complexity: **2** ; importance: **3**; author: **docentmail**

**Question:** Write the snippet into a single line. Insert semicolons to make the snippet understandable and not to change the snippet logic.

x = d (f+g ).some_method()

complexity: **2** ; importance: **3**; author: **docentmail**

**Question:** What is result of execution of the snippet?

function a(){ return 1; } alert (a());

complexity: **2** ; importance: **3**; author: **docentmail**

**Question:** Is this a valid JavaScript snippet?

var foo = 10 alert(foo)

complexity: **2** ; importance: **3**; author: **docentmail**

**Question:** Are these a valid JavaScript statements?

i ++;

i ++;