Java if语句用于测试条件。它检查布尔条件为:true 或 false。
语法格式:
if(condition){ //if语句块 => code to be executed. }
//实例:
public class IfExample{
public static void main(String [] args){
int age = 27;
if (age>18){
System.out.print("Age is greater than 18.");
}
}
if(condition){ //code if condition is true }else{ //code if condition is false }
//实例:
public class IfElseExample{
public static void main(String [] args){
int number =13;
if (number % 2 == 0){
System.out.println("这是一个偶数。");
}else{
System.out.println("这是一个奇数。");
}
}
}
if (){ //code to be executed if condition1 is true. }else if (){ //code to be executed if condition2 is true. }else if (){
//code to be executed if condition3 is true. }else{
//code to be executed if all the conditions are false.
}
//实例:
public class IfElseExample{
public static void main(String [] args){
int marks = 65;
if (marks<50){
System.out.println("fail");
}else if (marks >= 50 && marks < 60){
System.out.println("D grade");
}else if (marks >= 60 && marks < 70){
System.out.println("C grade");
}else if (marks >= 70 && marks < 80){
System.out.println("B grade");
}else if (marks >= 80 && marks < 90){
System.out.println("A grade");
}else if (marks >= 90 && marks <100){
System.out.println("A+ grade");
}else{
System.out.println("Invalid!");
}
}
}