Python函式基礎
阿新 • • 發佈:2022-05-03
運算子
Java語言支援如下運算子:
算術運算子:+,-,*,/,%,++,--
賦值運算子:=
關係運算符:>,<,>=,<=,==,!=,instanceof
public static void main(String[] args) { //二元運算子 int a = 10; int b = 20; System.out.println(a + b); System.out.println(a - b); System.out.println(a * b); System.out.println((float) a / b); System.out.println(a > b); System.out.println(a < b); System.out.println(a == b); System.out.println("-------分---------割--------------線-------"); //若運算中有long型別數值,則結果為long,若沒有,則為int long c = 12312321231232L; int d = 123; short e = 10; byte f = 8; System.out.println(c+d+e+f); //long System.out.println(d+e+f); //int System.out.println(e+f); //int }
public static void main(String[] args) { // ++:自增 --:自減 int a = 3; int b = a++; //先給b賦值,再自增 System.out.println(a); // 4 System.out.println(b); // 3 int c = ++a; //先自增,再給c賦值 System.out.println(a); // 5 System.out.println(c); // 5 }
邏輯運算子:&&,||,!
public class Study{ public static void main(String[] args) { //&& : and || : or ! : not boolean a = true; boolean b = false; System.out.println(a && b); //false System.out.println(a || b); //true System.out.println(!(a && b)); //true //短路運算 int c = 5; boolean d = (c<4)&&(c++<10); //檢測到c<4時便直接輸出false,故c++沒有被執行 System.out.println(d); System.out.println(c); }
位運算子:&,|,^,~,>>,<<,>>>
public static void main(String[] args) {
/*
A = 0011 1100
B = 0000 1101
A&B = 0000 1100
A|B = 0011 1101
A^B = 00110001
~B = 1111 0010
*/
// 面試題,最快方式算出2*8
System.out.println(2<<3);
/*
原理:
0000 0001 1
0000 0010 2
0000 0100 4
0000 1000 8
0001 0000 16
故<< = *2
>> = /2
*/
}
條件運算子:?,:
//三元運算子
// x ? y : z //如果x==true,則結果為Y,否則結果為z
int score = 80;
String type = score <60 ? "不及格" : "及格";
System.out.println(type);
擴充套件賦值運算子:+=,-=,*=,/=
public static void main(String[] args) {
int a = 10;
int b = 20;
System.out.println(a += b); //a += b 等同 a = a+b
}