String Methods

Question 1

Length

Answer 1

Find the length of a string
var.length

Question 2

.trim()

Answer 2

Removing white space
Used when processing the string of a user input field

Question 3

.includes()

Answer 3

Determines if string contains substring
returns true or false
Used for string matching or searching/parsing

Question 4

.indexOf()

Answer 4

Finding the index of a substring
returns the index of the substring within the string
if no substring, returns -1
Used to check if index is greater than -1 (aka does the substring exist within the string?) using a conditional

Question 5

.toUpperCase()

Answer 5

returns a string with all uppercase letters

Question 6

.toLowerCase()

Answer 6

returns string in lower case letters

Question 7

.replace()

Answer 7

Replaces strings with new values
returns a string with a pattern replaced by a replacement string
using regex- can globally replace
using string - can only replace the first occurence

ex: const str = ‘hello world! my name is also world.”
const stringPattern = ‘world’
const regexPattern = /world/gi
const replacement = ‘gitconnected’

console.log(str.replace(stringPattern, replacement)) //Hello gitconnected! my name is also world
console.log(str.replace(regexPattern, replacement)) //Hello gitconnected! my name is also gitconnected.

Question 8

.slice()

Answer 8

• returns a section of a string
• extracts a section of a string based on the index (first param is the first index, second is optional ending)
• negative begin index: slice backwards from the end
• can use with indexOf() as a reference point

Question 9

.split()

Answer 9

• converts into an array
• This is useful when you know your string uses a certain character to separate data, or if you want to operate on specific substrings individually.

Question 10

.repeat()

Answer 10

Repeats a string a specified number of times
pass number of times as the param

Question 11

.match()

Answer 11

Returns array of matching strings (returns the ones that match) when comparing a string against a regular expression

Question 12

.charAt()

Answer 12

Returns a character at an index
param is the index num

Question 13

.charCodeAt()

Answer 13

Returns the unicode of the char at a specified index
(UTF-16 cone integer between 0 and 65535.)