Java Library Functions | Programiz D11 Phase 2 Skip to main content

Java ArrayList Methods

inserts the element to the arraylist

adds all elements of a collection to arraylist

removes all the elements from arraylist

makes a copy of the array list

checks if the element is present in the arraylist

checks if a collection is a subset of arraylist

set the size of an araylist

performs an action to all elements of arraylist

returns the element present in the specified index

returns the position of the specified element

checks if the arraylist is empty

returns an iterate to loop through the ArrayList

returns position of last occurrence of the element

removes the single element from the arraylist

removes multiple elements from the arraylist

removes element that satisfy the condition

removes a portion of the arraylist

replace all elements from the arraylist

retains only the common elements

replace the single element from an arraylist

returns the length of an arraylist

sorts the arraylist according to specified order

returns a portion of the arraylist

converts an arraylist to an array

converts the arraylist into a String

trims the capacity of arraylist equal to the size

Java HashMap Methods

remove all elements from HashMap

makes the copy of the hashmap

computes a new value for the specified key

computes value if mapping for key is not present

computes a value for the mapping if key is present

checks if the specified key is present in HashMap

checks if HashMap contains the specified value

returns a set view of all entries

performs the action to all entries of HashMap

returns the value using the specified key

returns specified default value if key not found

checks if the HashMap is empty

returns a set view of all the keys of HashMap

merges the specified mapping to the HashMaps

inserts the specified item to the hashmap

inserts all items from a map to HashMap

inserts item if the key is not already present

removes the mapping for the specified key

replaces the value for the specified key

replaces all values with

returns the number of items in HashMap

returns a view of all values present in HashMap

Java Math Methods

returns the absolute value of a number

returns the arc cosine of the specified value

adds the specified numbers and returns it

returns the arc sine of the specified argument

returns the inverse tangent function of a value

returns θ converting coordinates (x, y) to (r, θ)

returns the cube root of the specified number

rounds the specified value upward

copies the sign of second argument to the first

returns the cosine of the specified angle

returns hyperbolic cosine of the specified value

subtracts 1 from specified number and returns it

returns e raised to power of given value

returns e raised to power of given value minus 1

rounds the specified value downward and returns it

returns the unbiased exponent of specified number

computes the hypotenuse of a right-angle triangle

returns the remainder as per the IEEE 754 standard

adds 1 to the specified number and returns it

returns the natural logarithm of specified value

returns the base 10 logarithm of specified value

returns natural logarithm of (specified value + 1)

returns the maximum value among the arguments

returns the smaller value among the arguments

multiplies the specified numbers and returns it

negates the specified variable and returns it

returns number adjacent to specified number

returns number less than and adjacent to the value

returns number greater than and adjacent to value

returns first argument raised to power of second

returns closest mathematical integer of the vaue

rounds the specified argument and returns it

returns the sine of the specified angle in radians

returns the hyperbolic sine of the specified value

returns the square root of the specified number

subtracts the specified numbers and returns it

returns the tangent value of the specified angle

returns hyperbolic tangent of the specified value

converts angle from radians to degrees

returns the int value from specified long argument

converts angle from degree to radians

returns a random value between 0.0 and 1.0

Java Object Methods

creates a copy of the object

checks if two objects are equal

returns the class name of the object

returns the hashcode value of the object

converts an object into the string

Java String Methods

Returns the character at the given index

Compares two strings in the dictionary order

Compares two strings ignoring case differences

Concatenates two strings and returns it

Checks whether the string contains a substring

Checks whether the string is equal to charSequence

Checks if the string ends with the given string

Compares two strings

Compares two strings ignoring case differences

Returns a formatted string

Encodes the string into a sequences of bytes

Returns a hash code for the string

Returns the index of the character/substring

Returns a canonical representation of the string

Checks whether a string is empty or not

Joins the given strings using the delimiter

Returns the length of the string

checks whether the string matches the given regex

Replace all matching characters/text in the string

Replace all substrings matching the regex pattern

Replace the first matching substring

Splits the string at the specified string (regex)

Checks if the string begins with the given string

Returns a subsequence from the string

Returns a substring from the given string

Converts the string to a char array

Converts characters in the string to lower case

Removes any leading and trailing whitespace

Returns the string representation of a value