Strings : Methods and Properties

Question 1

string.split()

Answer 1

Separates the characters or words within a string into an array. Optional separator parameter (“” or “ “) separates by each character or by word, respectively. No separator returns the entire string as one element in the array

Question 2

string.replace(substr | regexp, new SubStr | function())

Answer 2

Returns a new string with some or all matches of a pattern of characters replaced by a new pattern. 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.

Question 3

string.length

Answer 3

This property returns the number of code units in the string. UTF-16, the string format used by JavaScript, uses a single 16-bit code unit to represent the most common characters, but needs to use two code units for less commonly-used characters, so it’s possible for the value returned by length to not match the actual number of characters in the string.

For an empty string, length is 0.

Question 4

string.substr()

Answer 4

The substr() method returns the characters in a string beginning at the specified location through the specified number of characters.

syntax: str.substr(start[, length])

Parameters:
start
Location at which to begin extracting characters. If a negative number is given, it is treated as strLength + start where strLength is the length of the string (for example, if start is -3 it is treated as strLength - 3.)

length
Optional. The number of characters to extract.

Question 5

string.slice()

Answer 5

The slice() method extracts a section of a string and returns a new string.

Syntax: str.slice(beginSlice[, endSlice])

Parameters:

beginSlice
The zero-based index at which to begin extraction. If negative, it is treated as sourceLength + beginSlice where sourceLength is the length of the string (for example, if beginSlice is -3 it is treated as sourceLength - 3).

endSlice
Optional. The zero-based index at which to end extraction. If omitted, slice() extracts to the end of the string. If negative, it is treated as sourceLength + endSlice where sourceLength is the length of the string (for example, if endSlice is -3 it is treated as sourceLength - 3).