Conditionals & Logic

if Statement

An if statement is used to test an expression for truth.

If the condition evaluates to true, then the code within the block is executed;
otherwise, it will be skipped.

if (a == 10) {
  // Code goes here

else Clause

An else clause can be added to an if statement.

  • If the condition evaluates to true, code in the if part is executed.
  • If the condition evaluates to false, code in the else part is executed.
if (year == 1991) {
  // This runs if it is true
else {
  // This runs if it is false

else if Statement

One or more else if statements can be added in between the if and else to provide additional condition(s) to check.

if (apple > 8) {
  // Some code here
else if (apple > 6) {
  // Some code here
else {
  // Some code here

switch Statement

A switch statement provides a means of checking an expression against various cases.

  • If there is a match, the code within starts to execute.
  • The break keyword can be used to terminate a case.
  • default is executed when no case matches.
switch (grade) {
  case 9:
    std::cout << "Freshman\n";
  case 10:
    std::cout << "Sophomore\n";
  case 11:
    std::cout << "Junior\n";
  case 12:
    std::cout << "Senior\n";
    std::cout << "Invalid\n";

Relational Operators

Relational operators are used to compare two values and return true or false depending on the comparison:

  • == equal to
  • != not equal to
  • >greater than
  • < less than
  • >= greater than or equal to
  • <= less than or equal to

Logical Operators

Logical operators can be used to combine two different conditions.

  • && requires both to be true (and)
  • || requires either to be true (or)
  • ! negates the result (not)