Decision Making and Branching in Java
In java decision making and branching statements allow your program to evaluate situations and select the best course of action. This is accomplished by using different types of conditional statements such as if, switch and loop statements along with logical operators.
The if statement evaluates a conditional expression and executes a code block if the expression is true. It also allows for nested if statements.
If Statement
The if statement is the simplest form of conditional control in Java. It tests a condition and decides whether or not a block of statements should be executed based on the result. If the condition is true, the statements in the if block will be executed; otherwise, the instructions in the else block will be executed.
An if statement is comprised of the keyword if and a boolean value enclosed in curly brackets. When the if statement is evaluated by the computer, the boolean value will be tested against a series of possible outcomes. If the if statement evaluates to be true, a course of action is taken; if it evaluates to be false, another course of action is taken.
An if-else ladder is a more complex version of the if statement that allows you to check multiple conditions. A switch statement is also a conditional statement that directs program flow based on different cases, but it works with one variable rather than several.
If-Else Statement
The if-else statement allows the code to execute in different ways depending on the condition. The if-else ladder statement is an advanced version of this and can be used to check multiple conditions. It also enables you to define multiple else code blocks.
When the if-else statement is executed, it evaluates the test expression and then executes the code present inside the if block if the condition is true. If the condition is false, the code present outside the if block gets evaluated by default.
The if-else statement is one of the most basic statements in java and can be used to perform many conditional tasks such as calculating grades or assigning them to students based on their scores. You can also use an elif statement, which is an extension of the if-else statement. The elif statement must be followed by the code and should be indented with four spaces to make it clear that it is part of an if-else block.
Switch Statement
The switch statement lets you execute different blocks of code based on the value of an expression. It’s often used when there are multiple possible values for the expression and you need to compare them with a number of case constants. Using the switch statement is much easier than a series of if-else statements.
The computer evaluates the expression and if it matches one of the case constants, it then executes the statement associated with that case. If the expression doesn’t match any of the cases, it then executes the statement for the default case.
It’s usually best to put the default case at the end of all the possible cases, but it can be placed anywhere in a switch block. You can also include a break statement, which breaks out of the switch block and executes the code after it. This can be useful when you need to stop the switch from running too many cases.
Loop Statement
The Loop Statement allows programmers to repeat a set of instructions until a specified condition is met. It is an essential Java decision-making construct that allows programmers to create more flexible and dynamic code. Java provides several jump statements that alter typical control flow within loops and switch statements. These include break, continue, and return.
The simplest form of decision-making statements is the if statement. This statement checks whether a particular condition is true or false and executes a block of statements accordingly.
The if-else statement is similar to the if statement in that it also checks for a condition and executes a block of statements if it is true. The difference is that the if-else statement also contains an else clause to execute a different block of statements if the condition is not met. This makes the if-else statement more efficient than the if statement and helps to make the code more concise.