Mozilla "strings"

Question 1

The String object’s _________method returns a new string consisting of the single UTF-16 code unit located at the specified offset into the string.

Answer 1

charAt()

Question 2

The ______ method concatenates the string arguments to the calling string and returns a new string.

Answer 2

concat()

Question 3

The _______ method determines whether a string ends with the characters of a specified string, returning true or false as appropriate.

Answer 3

endsWith()

Question 4

the endsWith() returns __________

Answer 4

a boolean

Question 5

const str1 = ‘Cats are the best!’;

console.log(str1.endsWith('best', 17));
// expected output: 

const str2 = ‘Is this a question’;

console.log(str2.endsWith('?'));
// expected output:

Answer 5

true

false

Question 6

const str1 = 'Cats are the best!';
console.log(str1.endsWith('best!', 17));
// expected output:

Answer 6

false

Question 7

The __________method determines whether one string may be found within another string, returning true or false as appropriate.

Answer 7

includes()

Question 8

includes() returns a _____________

Answer 8

boolean

Question 9

The _____________method returns the index within the calling String object of the first occurrence of the specified value, starting the search at fromIndex. Returns -1 if the value is not found.

Answer 9

indexOf()

Question 10

var paragraph = ‘The quick brown fox jumps over the lazy dog. If the dog barked, was it really lazy?’;

var searchTerm = 'dog';
var indexOfFirst = paragraph.indexOf(searchTerm);

console.log(indexOfFirst);
// expected output: \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_

Answer 10

40

Question 11

The _____________ method returns the index within the calling String object of the last occurrence of the specified value, searching backwards from fromIndex. Returns -1 if the value is not found.

Answer 11

lastIndexOf()

Question 12

The ______________ method returns the calling string value converted to uppercase (the value will be converted to a________ if it isn’t one).

Answer 12

toUpperCase()

string

Question 13

The ____________ method returns the calling string value converted to lower case.

Answer 13

toLowerCase()

Question 14

The ____________ method removes whitespace from both ends of a string. Whitespace in this context is all the whitespace characters (space, tab, no-break space, etc.) and all the line terminator characters (LF, CR, etc.).

Answer 14

trim()

Question 15

var greeting = '   Hello world!   ';
console.log(greeting.trim());

Answer 15

“Hello world!”

Question 16

The _____________ method removes whitespace from the end of a string. trimRight() is an alias of this method.

Answer 16

trimEnd()

Question 17

var greeting = ‘ Hello world! ‘;

console.log(\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_);
// expected output: "   Hello world!";

Answer 17

greeting.trimEnd()

Question 18

The _____________ method removes whitespace from the beginning of a string. trimLeft() is an alias of this method

Answer 18

trimStart()

Question 19

var greeting = '   Hello world!   ';
console.log(\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_);
// expected output: "Hello world!   ";

Answer 19

greeting.trimStart()

Question 20

The ____________ method splits a String object into an array of strings by separating the string into substrings, using a specified separator string to determine where to make each split.

Answer 20

split()

Question 21

var str = ‘The quick brown fox jumps over the lazy dog.’;

var words = str.split(' ');
console.log(words[3]);
// expected output:

Answer 21

“fox”

Question 22

var str = ‘The quick brown fox jumps over the lazy dog.’;

var words = str.split(' ');
console.log(\_\_\_\_\_\_\_\_\_\_);
// expected output: "fox"

Answer 22

words[3]

Question 23

var str = ‘The quick brown fox jumps over the lazy dog.’;

var chars = str.split('');
console.log(chars[8]);
// expected output:

Answer 23

“k”

Question 24

var str = ‘The quick brown fox jumps over the lazy dog.’;

var chars = str.split('');
console.log(\_\_\_\_\_\_\_\_\_\_);
// expected output: "k"

Answer 24

chars[8]

Question 25

The split() method splits a String object into an __________ of strings by separating the string into substrings, using a specified separator string to determine where to make each split.

Answer 25

array

Question 26

split()

Answer 26

method splits a String object into an array of strings by separating the string into substrings, using a specified separator string to determine where to make each split.

Question 27

includes()

Answer 27

determines whether one string may be found within another string, returning true or false as appropriate.

Question 28

The ___________method returns the part of the string between the start and end indexes, or to the end of the string.

Answer 28

substring()

Question 29

var str = ‘Mozilla’;

console.log(str.substring(1, 3));
// expected output: 

console.log(str.substring(2));
// expected output:

Answer 29

“oz”

“zilla”

Question 30

str.substring(_________[,_________])

Answer 30

indexStart

indexEnd

Question 31

const str1 = 'Cats are the best!';
console.log(str1.endsWith('best!'));

Answer 31

true

Question 32

The __________method pads the current string with a given string (repeated, if needed) so that the resulting string reaches a given length. The padding is applied from the end (right) of the current string.

Answer 32

padEnd()

Question 33

const str1 = ‘Breaded Mushrooms’;

console.log(str1.padEnd(25, '.'));
// expected output: 

const str2 = ‘200’;

console.log(str2.padEnd(5));
// expected output:

Answer 33

“Breaded Mushrooms……..”

“200 “

Question 34

The ______ method pads the current string with another string (multiple times, if needed) until the resulting string reaches the given length. The padding is applied from the start (left) of the current string.

Answer 34

padStart()

Question 35

const str1 = ‘5’;

console.log(str1.padStart(2, 0));
// expected output:

Answer 35

“05”

Question 36

const fullNumber = '2034399002125581';
const last4Digits = fullNumber.slice(-4);
const maskedNumber = last4Digits.padStart(fullNumber.length, '*');

console.log(maskedNumber);
// expected output:

Answer 36

“****5581”

Question 37

const str1 = ‘5’;

console.log(str1.padStart(2));
// expected output:

Answer 37

” 5”

Question 38

The _______ method extracts a section of a string and returns it as a new string, without modifying the original string.

Answer 38

slice()

Question 39

var str = ‘The quick brown fox jumps over the lazy dog.’;

console.log(str.slice(31));
// expected output:

Answer 39

“the lazy dog.”

Question 40

var str = ‘The quick brown fox jumps over the lazy dog.’;

console.log(str.slice(4, 19));
// expected output:

Answer 40

“quick brown fox”

Question 41

var str = ‘The quick brown fox jumps over the lazy dog.’;

;console.log(str.slice(-4));
// expected output:

Answer 41

“dog.

Question 42

var str = ‘The quick brown fox jumps over the lazy dog.’;

console.log(str.slice(-9, -5));
// expected output:

Answer 42

“lazy”

Question 43

The ___________ method determines whether a string begins with the characters of a specified string, returning true or false as appropriate.

Answer 43

startsWith()

Question 44

const str1 = 'Saturday night plans';
console.log(str1.startsWith('Sat', 3));
// expected output:

Answer 44

false

Question 45

const fullNumber = '2034399002125581';
const last4Digits = fullNumber.slice(-4)

console.log(last4Digits);

Answer 45

5581

Question 46

‘abc’.padStart(1); //

Answer 46

“abc”

Question 47

‘abc’.padStart(10, “foo”); //

Answer 47

“foofoofabc”

Question 48

‘abc’.padStart(6,”123465”); //

Answer 48

“123abc”

Question 49

‘abc’.padStart(8, “0”); //

Answer 49

“00000abc”