JavaScript - String Methods

Question 1

replace()

Answer 1

Returns: new string
The original string is left unchanged.

some or all matches of a pattern replaced by a replacement.

The pattern can be a string or a RegExp, and the replacement can be a string or a function to be called for each match.

If pattern is a string, only the first occurrence will be replaced.

Question 2

slice()

Answer 2

Returns: a new string
The original string is left unchanged.

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

Question 3

split()

Answer 3

Returns: an array of strings
Changes the original string in place

divides a String into an ordered set of substrings, puts these substrings into an array, and returns the array. The division is done by searching for a pattern; where the pattern is provided as the first parameter in the method’s call.

E.g. const str = ‘The quick brown fox jumps over the lazy dog.’;

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

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

const strCopy = str.split();
console.log(strCopy);
// expected output: Array ["The quick brown fox jumps over the lazy dog."]

Question 4

charAt()

Answer 4

Returns: new string

returns a new string consisting of the single UTF-16 code unit located at the specified offset into the string.

Question 5

concat()

Answer 5

Returns: A new string containing the combined text of the strings provided.

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

const str1 = 'Hello';
const str2 = 'World';

console.log(str1.concat(' ', str2));
// expected output: "Hello World"

console.log(str2.concat(', ', str1));
// expected output: "World, Hello"

Question 6

includes()

Answer 6

Returns: true if the search string is found anywhere within the given string; otherwise, false if not.

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

Question 7

endsWith()

Answer 7

Returns: returning true or false as appropriate.

method determines whether a string ends with the characters of a specified string

Question 8

match()

Answer 8

Returns: An Array whose contents depend on the presence or absence of the global (g) flag, or null if no matches are found.

method retrieves the result of matching a string against a regular expression.