R If 语句

if(boolean_expression) {
  //If the boolean expression is true, then statement(s) will be executed. 
}

x <-24L  
y <- "learnfk"  
if(is.integer(x))  
{  
    print("x is an Integer")  
}  

x <-20  
y<-24  
count=0  
if(x<y)  
{  
    cat(x,"is a smaller number\n")  
    count=1  
}  
if(count==1){  
    cat("LEARNFK is successfully execute")  
}  

x <-1  
y<-24  
count=0  
while(x<y){  
    cat(x,"is a smaller number\n")  
    x=x+2  
    if(x==15)  
        break  
}  

x <-24  
if(x%%2==0){  
    cat(x," is an even number")  
}  
if(x%%2!=0){  
    cat(x," is an odd number")  
}  

year1 = 2021
if(year1 %% 4 == 0) {
 if(year1 %% 100 == 0) { 
	 if(year1 %% 400 == 0) { 
		 cat(year1,"is a leap year") 
		} else {
		 cat(year1,"is not a leap year") 
		}
	} else {
	 cat(year1,"is a leap year") 
	}
} else {
 cat(year1,"is not a leap year") 
}