Java instructions are fundamental elements that define the actions to be executed by the Java Virtual Machine (JVM). Here is a summary of the main types of Java instructions:

1. Block instructions

• Simple instruction : Ends with a semicolon ;.

• Compound instruction (block) : Allows you to group several instructions. It is delimited by curly braces { }.

• Variable visibility : Variables declared in a block are visible only in that block and nested blocks.

2. The assignment

• Syntax :variable = expression;

• Example :int x = 5;

3. The conditions

• Instructionif : Allows a block of code to be executed if a condition is true. java if (condition) { // instructions à exécuter }

• Instructionif...else : Allows execution of a block of code if the condition is true, otherwise another block. java if (condition) { // instructions si vrai } else { // instructions si faux }

4. Iterations

• Loopfor : Allows you to repeat a block of code a specified number of times. java for (initialisation; condition; incrémentation) { // instructions à répéter }

• Loopwhile : Allows you to repeat a block of code as long as a condition is true. java while (condition) { // instructions à répéter }

5. Break and continue

• break: Allows you to immediately exit a loop or a switch.

• continue: Allows you to move to the next iteration of a loop.

6. Try...catch

• Exception handling : Allows you to manage errors by capturing exceptions. java try { // code susceptible de générer une exception } catch (ExceptionType e) { // gestion de l'exception }

7. switch

• Instructionswitch : Evaluates a variable and executes the code block corresponding to the value of the variable. java switch (variable) { case valeur1: // instructions break; case valeur2: // instructions break; default: // instructions par défaut }

8. Other instructions

• Variable declarations : int a;,String monNom;

• Return instructions :return x;

• Increment instruction :y++;

These instructions allow you to structure and control the execution flow of a Java program.