java Math 함수 정리

import org.junit.jupiter.api.Test;import static org.assertj.core.api.Assertions.assertThat;/** * https://docs.oracle.com/javase/8/docs/api/java/lang/Math.html * */public class MathTest { @Test void abs() { assertThat(Math.abs(10)).isEqualTo(10); assertThat(Math.abs(-10)).isEqualTo(10); } @Test void ceil() { assertThat(Math.ceil(10.123)).isEqualTo(11); assertThat(Math.ceil(10.56)).isEqualTo(11); } @Test void floor() { assertThat(Math.floor(10.39)).isEqualTo(10); assertThat(Math.floor(10.56)).isEqualTo(10); } @Test void round() { assertThat(Math.round(10.39)).isEqualTo(10); assertThat(Math.round(10.56)).isEqualTo(11); } @Test void max() { assertThat(Math.max(10, 100)).isEqualTo(100); } @Test void min() { assertThat(Math.min(10, 100)).isEqualTo(10); } @Test void pow() { //거듭제곱 assertThat(Math.pow(2, 4)).isEqualTo(16); } @Test void sqrt() { assertThat(Math.sqrt(25)).isEqualTo(5); assertThat(Math.sqrt(26)).isEqualTo(5.0990195135927845); } @Test void addExact() { assertThat(Math.addExact(10, 30)).isEqualTo(40); assertThat(Math.addExact(30, 10)).isEqualTo(40); } @Test void subtractExact() { assertThat(Math.subtractExact(10, 30)).isEqualTo(-20); assertThat(Math.subtractExact(30, 10)).isEqualTo(20); } @Test void decrementExact() { assertThat(Math.decrementExact(10)).isEqualTo(9); assertThat(Math.decrementExact(318)).isEqualTo(317); } @Test void multiplyExact() { assertThat(Math.multiplyExact(10, 20)).isEqualTo(200); } @Test void toIntExact() { assertThat(Math.toIntExact(128902389L)).isEqualTo(128902389); }}