java条件判断语句有哪些类型的方法呢英语

Introduction

Java is one of the most popular programming languages that are commonly used to develop web and mobile applications. It is an object-oriented language that provides a lot of features to make programming efficient and effective. One of the primary features of Java is its conditional statement that allows developers to make decisions based on certain conditions. In this article, we will discuss the different types of conditional statements that Java provides with examples.

If statement

The if statement is the basic conditional statement in Java that allows a program to make decisions based on the result of a logical expression. The if statement begins with the keyword "if" followed by a logical expression enclosed in parentheses. If the logical expression evaluates to true, then the code inside the if block will be executed, and if the expression evaluates to false, then the if block will be skipped.

Here is an example of an if statement:

if(num > 10){

System.out.println("The number is greater than 10");

}

In this example, if the value of the variable "num" is greater than 10, then the statement inside the if block will be executed, which is to print the message "The number is greater than 10."

If-else statement

The if-else statement is another type of conditional statement that allows a program to execute different blocks of code based on the result of a logical expression. The if-else statement begins with the keyword "if" followed by a logical expression enclosed in parentheses. If the logical expression evaluates to true, then the code inside the if block will be executed, and if the expression evaluates to false, then the code inside the else block will be executed.

Here is an example of an if-else statement:

if(num > 10){

System.out.println("The number is greater than 10");

} else {

System.out.println("The number is less than or equal to 10");

}

In this example, if the value of the variable "num" is greater than 10, then the statement inside the if block will be executed, which is to print the message "The number is greater than 10." Otherwise, the statement inside the else block will be executed, which is to print the message "The number is less than or equal to 10."

Switch statement

The switch statement is another type of conditional statement that allows a program to execute different blocks of code based on the value of an expression. The switch statement begins with the keyword "switch" followed by an expression enclosed in parentheses. The value of the expression is then compared to the values in each case statement. If the value of the expression matches the value in a case statement, then the statements inside that case block will be executed. If the value of the expression does not match any of the case statements, then the statements inside the default block will be executed.

Here is an example of a switch statement:

switch(dayOfWeek){

case 1:

System.out.println("Monday");

break;

case 2:

System.out.println("Tuesday");

break;

case 3:

System.out.println("Wednesday");

break;

default:

System.out.println("Invalid day of the week");

break;

}

In this example, if the value of the variable "dayOfWeek" is 1, 2, or 3, then the corresponding case block will be executed, which is to print the name of the day of the week. Otherwise, the default block will be executed, which is to print the message "Invalid day of the week."

Conclusion

Java provides various types of conditional statements that allow a program to make decisions based on certain conditions. These statements include if, if-else, and switch statements. By using these statements, developers can create programs that can make decisions and perform different actions based on specific criteria.