class java.lang.Object
// all classes inherit and may override these methods

• boolean equals(Object other)
• String toString()

• int compareTo(Object other)
  // return value // return value = 0 if this is equal to other
  // return value > 0 if this is greater than other class java.lang.Integer implements java.lang.Comparable
  • Integer(int value)
    // constructor
  • int intValue()
  class java.lang.Double implements java.lang.Comparable
  • Double(double value)
    // constructor
  • double doubleValue()
  class java.lang.String implements java.lang.Comparable
  • int length()
  • String substring(int from, int to)
    // returns the substring beginning at from
    // and ending at to-1
  • String substring(int from)
    // returns substring(from, length())
  • int indexOf(String s)
    // returns the index of the first occurrence of s;
    // returns -1 if not found
  class java.lang.Math
  
  • static int abs(int x)
  • static double abs(double x)
  • static double pow(double base, double exponent)
  • static double sqrt(double x)
  class java.util.Random
  • int nextInt(int n)
    // returns an integer in the range from 0 to n-1 inclusive
  • double nextDouble()
    // returns a double in the range [0.0, 1.0)
  class java.util.ArrayList
  • int size()
  • boolean add(Object x)
    // appends x to the end of list; returns true
  • Object get(int index)
    // returns the element at the specified position
  • Object set(int index, Object x)
    // replaces the element at index with x
    // returns the element formerly at the specified position
  • void add(int index, Object x)
    // inserts x at position index, sliding elements
    // at position index and higher to the right
    // (adds 1 to their indices) and adjusts size
    
  • Object remove(int index)
    // removes element from position index, sliding elements
    // at position index + 1 and higher to the left
    // (subtracts 1 from their indices) and adjusts size
    // returns the element formerly at the specified position
  
  
  

  See also...

  • Computer Science A & AB: Introduction of Java in 2003-2004
  • Computer Science AB: Quick Reference Guide