Control Flow and Logic in Java

Back to Java for DSA
Arjit Sharma
01 Min

Conditional Statements

Used to perform different actions based on different conditions.

If-Else

int age = 25;

if(age > 18){
    // Code for adults
} else if(age < 30) {
    // Code for young adults
} else {
    // Code for others
}

Switch Case

An alternative to many if-else statements, great for handling multiple specific values.

String test = "a";

switch(test) {
    case "a":
        // code for case "a"
        break;
    case "b": 
        // code for case "b"
        break;
    default: 
        // default code
}

Loops in Java

Loops let you repeat blocks of code until a condition is met.

🔹 For Loop Used when the number of iterations is known.

for(int i = 0; i < 5; ++i){
    // Code executes 5 times
}

🔹 While Loop Executes as long as a condition is true.

int i = 0;
while(i < 5){
    // Code
    i++;
}

🔹 Do-While Loop Executes the code block at least once, then repeats while condition is true.

int i = 3;
do {
    // Code
    i -= 1;
} while(i != 0);

🔹 For-Each Loop Perfect for iterating through arrays or collections.

String[] humans = {"arjit", "raman", "albert"};

for(String human : humans){
    System.out.println(human);
}
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