Java Conditional Statements: If, Else and Switch

07 Feb 2023
Beginner
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Java Conditional Statements: If, Else and Switch

What are Conditional Statements in Java?

Conditional statements are one of the significant parts of "Control Structure" in Java. Conditional statements are based on certain conditions and generate decisions accordingly. These statements are a bunch of codes that can be executed by "decisions statements". These conditions have some specific "boolean expressions". The boolean expression of these conditional statements generates "Boolean Value" which could be either true or false.

Types of Conditional Statements in Java

There are 4 types of conditional statements. They are "If statements" in Java, "If else statements" in Java, "Ladder statements or If Else If statements", and "Switch statements". These will be discussed further.

If..statement in Java

  • “If” is a statement execution that depends on certain conditions.
  • These conditions only follow the "if" keyword.
  • The "If" statement depends on the expression of a certain boolean and generates a Boolean Value.
  • If the value is "True" then the execution will be done in the current block.
  • But if the Value is "false", it will switch to the next statement.

Syntax

If (condition)
{
//Statements to be executed
}

If...statement example in Java

class if_condition
{
    public static void main(String[] args)
   {
       double a = 0.8;
        if (a>0)
        {
          System.out.println(a + " is a Positive Number!");
        }
    }
}

Output

0.8 is a Positive Number!

If..else statement in Java

  • The if else statement Java is a particular control structure that depends on selecting the conditions of the chosen set of statements.
  • The if else program in java depends on two types of conditions, which are "If" and "Else".
  • If the expression generates the "true" value then it will execute the block "If" in the if-else program in the if else program in Java.
  • But if the value is "False", it will execute the "Else" block which depends on the if-else condition.

Syntax

if (condition)
{
//Statements to be executed if condition satisfies
}
else
{
//Statements to be executed if the condition is not satisfied
}

If-else example in Java

class if_else_condition
{
    public static void main(String[] args)
    {
        double a = -0.8;
        if (a>0)
        {
            System.out.println(a + " is a Positive Number!");
        }
        else
        {
            System.out.println(a + " is a Negative Number!"); 
        }
    }
}

Output

-0.8 is a Negative Number!

If..else...If statement in Java

  • This control structure statement depends on a series of tests in order to evaluate the solution
  • It is generated by the multiple uses of the "If Else" statement.
  • If the one condition meets the result then the first ladder will be executed.
  • But if the condition does not meet the results then the default "Else" statement will be executed.

Syntax

if (condition)
{
//Statements set 1
}
else if (condition 2)
{
//Statements set 2
}
 . . .
 else
{
//Statements to be executed if no condition is satisfied.
}

Example

class nested_if_else_condition
{
 public static void main(String[] args)
 {
 double total_marks = 382;
 char grade;
 double perc = (total_marks/500)*100;
 if (perc >= 80)
 {
 grade = 'A+';
 }
 else if ((perc >=70) && (perc <80))
 {
 grade = 'A'; 
 }
 else if ((perc >=60) && (perc <70))
 {
 grade = 'B+'; 
 }
 else
 {
 grade = 'B';
 }
 System.out.println("The percentage of the student is: " +perc);
 System.out.println("\n The grade of the student is: " +grade);
 
 }
}

Output

The percentage of the student is: 76.4

The grade of the student is: A+

Switch Statement in Java

  • This statement has multiple phases of execution.
  • Switch statements generally evaluate the result which is assisted by some "primitive type" of data or "class type" of data.
  • This statement has a test series of conditions that can do one or more cases at a time by switching expressions.
  • If the case meets the result then the statement will be executed.
  • But if it does not meet the result then the "default" cases will be executed.

Syntax

switch (Expression)
{
case value 1: Statement 1;

case value 2: Statement 2;

case value 3: Statement 3;
.
.
.
case value n: Statement n;

default: default statement;
}

Example

class Switch_Case {
    public static void main(String[] args)
    {
        char a = 'C';
        switch (a)
        {
            case 'A':
                System.out.println("Letter A");
                break;
            case 'C':
                System.out.println("Letter C");
                break;
            default:
                System.out.println("Default case: NO Letter Matched!");
        }
    }
}

Output

Letter C

If..else vs. Switch statements

Parameter If...Else Swich
Definition The execution of both of the "If" blocks and "else", depends on the condition stored in the if statement. The code blocks in the switch statement depend on the execution of multiple cases .
Usage This statement is used for pointer, character, integer, a boolean type, and floating point type. Switch statements are used for integer and character expressions
Testing It tastes equality and logical expression. It tests only equality
Expressions It generates multiple statements for multiple decisions. It generates single expression for multiple decisions.
Editing It is difficult to edit because of its nested type of program. It is very easy to edit
Value It is dependent on constraint. It is dependent on users .
Summary

This article gives a vast idea about the definition of a conditional statement and it's types. Features of every conditional operator in Java with examples and syntax. This article also includes the different types of conditional statements in java and the difference between the If-else condition and the switch condition.

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