Java control syntax

** What I learned today **

Instruction execution statement

java

System.out.println(); 
#The value taken as an argument is displayed on a new line.

System.out.print(); 
#Display the value taken as an argument without line breaks.

int variable name= Math.max( a , b ); 
#Compare the arguments and substitute the larger number.

int variable name= Integer.parseInt(String or String type variable); 
#Convert a string to a number. For example"100"And,,,

int variable name= new java.util.Random().nextInt(upper limit);
#nextInt();If you take a number as an argument with, numbers less than that number are randomly generated.(0~Less than the upper limit)

String variable name= new java.util.Scanner(System.in).nextLine();
#Accepts the input of one line of character string from the keyboard.

int variable name= new java.util.Scanner(System.in).nextInt();
#Accepts the input of one integer from the keyboard.

Typical control syntax

-** if statement (conditional branch) **

java

if (Conditional expression) {
If the condition is true, the processing of this block works.
} else {
If the condition is false, the processing of this block works.
}


#Also, if statements are nested(Nested)can do.
if (Condition 1) {
Processing when true#If false, move to condition 2.
} else if (Condition 2) {
Processing when true#If false, move to condition 3.
} else if (Condition 3) {
Processing when true#If false, move to else processing.
} else {
Processing when all are false
}

-** switch statement **

java

switch (Variable name) {
  case 〇〇:
Processing when the content of the variable is 〇〇
    break;

  case △△:
Processing when the content of the variable is △△
    break;

  case ××:
Processing when the content of the variable is XX
    break;

  default:
What to do if none of the cases apply(Can be omitted if not needed)
}

-The switch statement can only use an expression that compares whether the right side and the left side match. (<,>,! =, Etc. cannot be used)

-Can only be used with integers, strings, or characters to compare (decimal or boolean values cannot be used)

-Since the switch statement only jumps to the applicable case, if break is not described, the program will be read in sequence after jumping to a specific case.

• Break statement: A method that interrupts and terminates processing.

-** while statement (repeated) **

java

while (Conditional expression) {
Processing when true#Loop forever until true.
}

-** for statement (repeat specified number of times) **

java

for (Initialization process,Repeat condition,Repeated processing) {
Repeated processing
}

#For example
for (int i = 0, i < 10, i++) {
  System.out.println(i); 
}
#The variable i is initialized and 0 is assigned. Process in the block until i is greater than 10.
#I every time processing++(Add 1 to the variable i)The process is performed.

• What is a continue statement: The specified lap is interrupted and the next week is started.

• Scope: The range in which variables can be used. Variables within a block can only be used within that block. (The scope of the variable is within that block)