Basic Built-in Methods

All the methods that are being printed can also have their result set to a variable.

Anatomy of a Method

name(arg1, arg2 ...)

• name is where a method name would go

• () is where we can place our require arguments for the method

• arg1 is a placeholder for a possible argument

Example: System.out.println("Hello, World!")

• System.out.println is the name of our method

• "Hello, World!" is our argument provided to our method

Math Methods

double a = 10.3;
double b = 10.5;
double c = 10.6;

System.out.println(Math.round(a)); // Outputs: 10
System.out.println(Math.round(b)); // Outputs: 11
System.out.println(Math.round(c)); // Outputs: 11

Math.round() converts your double to the nearest integer value.

double val1 = 4.3;
System.out.println(Math.ceil(4.3)); // Outputs 5.0

double val2 = 4.8;
System.out.println(Math.floor(4.8)); // Outputs 4.0

Math.ceil() stands for "ceiling" and rounds a number up to the nearest integer.

For example, Math.ceil(4.3) would return 5.0.

Math.floor() stands for "floor" and rounds a number down to the nearest integer. For example, Math.floor(4.8) would return 4.0.

These functions are often used when you need to work with whole numbers or want to adjust a decimal number to the nearest integer in a specific direction

int x = 10;
int y = 5;

System.out.println(Math.min(x,y)); // Outputs: 5
System.out.println(Math.max(x,y)); // Outputs: 10

Math.min() will provide the smaller value between the two arguments provided

Math.max() will provide the larger value between the two arguments provided

double num =  25.0;
System.out.println(Math.sqrt(num)); // Outputs: 5

Math.sqrt will return a square root of the given numeric argument

double fun_value = Math.random();
System.out.println("Random: " + fun_value); // Outputs: Random: 0.1243868832888797

Math.random() requires no arguments; it generates a random number from 0 to 1 (not including)

For my execution of the code it generated 0.1243868832888797

Basic String Methods

String text = "Hello, World!";
int text_length = text.length(); // text_length is 13

Since text is a string type variable, we can access its methods (its super powers) by inserting a period. after the variable name.

.length() will provide the number of characters that made up the strings

String txt = "Hello World";
System.out.println(txt.toUpperCase());   // Outputs "HELLO WORLD"
System.out.println(txt.toLowerCase());   // Outputs "hello world"

.toUpperCase() converts the string to all uppercase

.toLowerCase() converts the string to all lowercase