CSE 121 Final Exam Reference Sheet

25wi ver.

Note: this is for the Winter 2025 iteration of CSE 121. Looking for a different quarter? Please visit https://courses.cs.washington.edu/courses/cse121/.

(DO NOT WRITE ANY WORK YOU WANTED GRADED ON THIS REFERENCE SHEET. IT WILL NOT BE GRADED)

type[] name = new type[length];
type[] name = {VAL1, VAL2, VAL3, ...};

type[][] name = new type[numRows][numColumns];
type[][] name = {
            {VAL1, VAL2, VAL3, ...},
            ...
            {VAL4, VAL5, VAL6, ...}
};

Using Arrays	Description
`int value = name[i]`	Get the value at index `i`
`name[i] = value`	Set the value at index `i`
`name.length`	Get the number of elements in `name`

Using 2D Arrays (rectangular)	Description
`int value = name[i][j]`	Get the value at row `i`, column `j`
`name[i][j] = value`	Set the value at row `i`, column `j`
`name.length`	Number of rows (number of inner arrays)
`name[0].length`	Number of columns (length of inner array)

String Method	Description
`charAt(i)`	Returns character in this String at index `i`
`contains(str)`	Returns `true` if this String contains `str` inside it, returns `false` otherwise
`startsWith(str)`	Returns `true` if this String starts with `str`, returns `false` otherwise
`endsWith(str)`	Returns `true` if this String ends with `str`, returns `false` otherwise
`equals(str)`	Returns `true` if this String is the same as `str`, returns `false` otherwise
`equalsIgnoreCase(str)`	Returns `true` if this String is the same as `str` ignoring capitalization, returns `false` otherwise
`indexOf(str)`	Returns the first index this String where `str` begins, returns `-1` if not found
`length()`	Returns the number of characters in this String
`replace(str, newStr)`	Returns a new String with all `str` in this String replaced with `newStr`
`substring(i)`	Returns characters in this String from index `i` (inclusive) to end (exclusive)
`substring(i, j)`	Returns characters in this String from index `i` (inclusive) to `j` (exclusive)
`toLowerCase()`	Returns an all-lowercase version of this String
`toUpperCase()`	Returns an all-uppercase version of this String

Random Method	Description
`nextInt(max)`	Returns a random integer from 0 (inclusive) to `max` (exclusive)
`nextInt(min, max)`	Returns a random integer from `min` (inclusive) to `max` (exclusive)

Math Method	Description
`Math.abs(val)`	Returns the absolute value of `val`
`Math.max(val1, val2)`	Returns the larger of the two values `val1` and `val2`
`Math.min(val1, val2)`	Returns the smaller of the two values `val1` and `val2`
`Math.pow(base, exp)`	Returns the value of `base` raised to the `exp` power
`Math.sqrt(val)`	Returns the square root of `val`

Scanner Method	Description
`next()`	Returns the next token as a String
`nextLine()`	Returns the entire line as a String
`nextInt()`	Returns the next token as an `int`, throws exception if cannot
`nextDouble()`	Returns the next token as a `double`, throws exception if cannot