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Conditionals

Types of Conditionals

A conditional in C can be written using if, else-if, else, ternary operators, andswitch` statements.

if Statements

An if statement tests an expression and executes code based on its truth.

if (x == 3) { printf("x is 3!"); }

else-if Statements

An else-if statement tests an expression and must come after an existing if or else-if.

if (x > 3) { printf("x is greater than 3"); } else if (x < 3) { printf("x is less than 3"); }

else Statements

An else statement is accessed when all preceding if and/or else-if statements return false.

if (x > 3) { printf("x is greater than 3"); } else if (x < 3) { printf("x is less than 3"); } else { printf("x equals 3"); }

Dangling else Statement

A dangling else statement results when it’s ambiguous which conditional the else statement is attached to.

Ternary Operators

A ternary operator is a condensed if-else statement.

min = a < b ? a : b; // This is the same as the if-else below if (a < b) { min = a; } else { min = b; }

switch Statements

A switch statement is a condensed series of cascading else statements. It tests a value and compares it against multiple cases.

switch (grade) { case 9: printf("Freshman\n"); break; case 10: printf("Sophomore\n"); break; case 11: printf("Junior\n"); break; case 12: printf("Senior\n"); break; default: printf("Invalid\n"); break; }

Operators and Conditionals

A conditional in C can use relational operators such as &&, ||, and ! to compare values and test multiple expressions.