关于前端工程师的一套英文题

1. You want to add some text inside a DIV called div1 so that the word Hello is shown in bold. Which code would you use?

A. $("#div1").text("<b>hello</b>");
B. $("#div1").html("<b>hello</b>");
C. $("#div1").attr("<b>hello</b>");
D. $("#div1").val("<b>hello</b>");

答案：B

2.You‘re using JQuery to write an AJAX call to fetch data from your web service. The operation will return a JSON result which is userd to display additional data to the user. Do you know which of these callbacks is executed last following an AJAX call?

A. Complete
B. Success
C. Error
D. None of these

答案：A

3.You want to user JQuery to select input elements where the elements name begins with the word "Range". Which code would you use?

A. $("input[name^= 'Range' ]")
B. $("input[name*= 'Range' ]")
C. $("input[name$= 'Range' ]")
D. $("input[name!= 'Range' ]")

答案：A

4. Inside one of your stylesheets you've added references to relative resources on the server such as images and fonts. Complete the following sentence,partial URLs are interpreted relative to the ___?

A. Web page location
B. Stylesheets location

答案：B

5.Which of the following layouts provides for the arrangement of elements on a page such that the elements behave predictably when the page layout must accommodate different screen sizes and display devices.

A. run-in
B. flexbox
C. inline-block
D. inline

答案：B

6.Which of the following values is NOT a valid choice for the text-transform property?

A. Italic
B. Capitalize
C. Uppercase
D. Lowercase

答案：A

7.Which lines of code (lettered to the right) have mistakes?

var age: prompt("Enter your age.");    //1
alert("The age is" + age)              //2
if (age >= 18 ) alert("Access granted!") //3
else if ( age = 16 || age = 17 ) {        //4
  alert("You will need a guardian to enter.");  //5
}                                               //6
else alert("Access forbidden.")            //7

A. 1,3,4,7
B. 1,2,3,4
C. 2,3,7
D. 3,4,7
E. 1,4

答案：E

8.Which of the following for loops will iterate the maximum number of times necessary to retrieve every element form an array with a length of 10?

A. 
    for (var i = 0; i < 9; i++) {
      // arr[i]
    }
B. 
    for (var i = 0; i <= 9; i++) {
      // arr[i]
    }
C. 
    for (var i = 0; i < 10; i++) {
      // arr[i]
    }
D. 
    for (var i = 0; i < 11; i++) {
      // arr[i]
    }

答案： B

9. Given the following array：

var arr = [
    {
        name: "Sarah",
        age: 29,
        hobbies: ["Tennis","Swimming","Painting"]
    },
    {
       name: “Bob”,
       age: 60,
       hobbies: ["Football","Golf","Programming"]
    }
];

A. arr[1][2][3];
B. arr[2].hobbies[3];
C. arr.hobbies[2];
D. arr[1]["hobbies"][2];
E. arr["Bob"].hobbies["Programming"];

答案：D

10.Which of the following is a valid variable name?

A. this
B. _ROOT_
C. delete
D. 10thItem
E. *

答案： B

11. What does this function do?

var x = function (value) {
    return !!value
}

A. It returns the inverse of the value.
B. It returns the value converted to a boolean.
C. It returns the value as-is.
D. It returns false no matter the value.
E. None of the above: it is syntactically invalid.

答案： B

12. Which best describes a prototype?

A. Instances of a class.
B. An extension of a class.
C. A parent object.
D. The chain of objects each individual object inherits.
E. An object whose properties and methods are inherited by other objects.

答案： E

13. Given the following code:

function myFunc () {
  setTimeout ( function () {
    console.log('a');
  })
    console.log('b');
}
console.log("c");
myFunc();
console.log("d");

A. c,b,d,a
B. c,d,a,b
C. c,d,a,b
D. c,b,a,d
E. c,a,b,d

答案：A

14. Which concept best explains why this is the case?

  document.body.hasOwnProperty("addEventListener"); //false
  'addEventListener' in document.body; //true

A. Property nesting.
B. Property sharing.
C. Object composition.
D. Method composition.
E. The prototype chain.

答案：E

15. The ability to call the function f above the point where it's declared,and the inabillity to do it with g , refers to which concept?

f();
function f () {}

g(); //Uncaught TypeError: g is not a function
var g = function () {};

A. Predeclaration
B. Closures
C. Memory allocation
D. Execution queue
E. Hoisting

答案：E

16. The same numbers and strings are considered equal,but arrays with the same items aren't.Which best describes why the arrays aren't equal?

5218 === 5218; //true
"string" === "string"; //true
[ 5218, "string"] === [ 5218, "string"]; //false

A. Both arrays are considered different objects and therefore are not equal when compared.
B. Arrays cannot be directly compared.
C. Numbers and strings within arrays cannot be directly compared.
D. The numbers and string within the array are nested one-level deep,preventing them from being compared.
E. Arrays can never be equal.

答案：A

17. In a browser,what are a, b and c?

var one = {
    prop: this,
    func: function () {
        return this;
    }
};
var two = {
    prop: one
};
var a = one.prop;
var b = one.func();
var c = one.func.call(two).prop;

A. All three are window.
B. a and b are one ,while c is two.
C. a is window , b is one and c is undefined.
D. a is undefined ,b is one and c is undefined.
E. a is window , while b and c are one.

答案：E

18.What's the value of:

(function () {
    let f = this ? class g { } : class h { };
    return [
      typeof f,
      typeof h
    ];
})();

A. ["function","undefined"]
B. ["function","function"]
C. ["undefined","undefined"]
D. Error

答案：A

19. What’s the value of:

[...[..."..."]].length

A. 1
B. 3
C. 6
D. Error

答案：B

20. Which of the following statement is valid to use a Node module fs in a Node based application?

A. var fs = require("fs");
B. var fs = import("fs");
C. package fs;
D. import fs;

答案： A