AP Java: Strings, Math, Constants & Static

String methods

length(), indexOf(), subString(), subString( , )

String Immutability

Once a String object is created, its value cannot be changed.

substring(int beginIndex, int endIndex)

Returns a new string from the start index up to, but not including, the end index.

indexOf(String str)

Returns the index of the first occurrence of str, or -1 if not found.

Math.random()

Returns a double value greater than or equal to 0.0 and less than 1.0.

Random integer formula (low to high)

(int)(Math.random() * (high - low + 1)) + low

Math.abs(x)

Returns the absolute value of x, can be int or double

Defined Constants (final)

Variables declared with 'final' whose values cannot be changed after initialization.

Constant Naming Convention

Written in all uppercase letters with words separated by underscores (e.g., MAX_VALUE).

static keyword

Indicates that a variable or method belongs to the class itself, rather than to a specific object instance.

Static method restriction

Static methods cannot access non-static instance variables or use the 'this' keyword.

Math.sqrt(x)

Returns the square root of x (non negative), is always double

Math.min(a,b)

Returns the smaller of a and b, two int or two double

Math.max(a,b)

Returns the greater of a and b, two int or two double