Rust Tutorial : Decision Making
from tutorialspoint.com

Conditional Statements
StatementDescription
if statementconsists of a Boolean expression followed by one or more statements.
if...else statement if statement can be followed by an optional else statement
executes when the Boolean expression is false
else...if and nested if statementcan use one if or else if statement inside another if or else if statement(s)
match statementallows a variable to be tested against a list of values (switch or case statement)
if Statement
syntax 
if boolean_expression {
   // statement(s) will execute if the boolean expression is true
}
if...else Statement
syntax 
if boolean_expression {
   // statement(s) will execute if the boolean expression is true
} else {
   // statement(s) will execute if the boolean expression is false
}
Nested if
syntax 
if boolean_expression1 {
   //statements if the expression1 evaluates to true
} else if boolean_expression2 {
   //statements if the expression2 evaluates to true
} else {
   //statements if both expression1 and expression2 result to false
}
match Statement
syntax 
let expressionResult = match variable_expression {
   constant_expr1 => {
      //statements;
   },
   constant_expr2 => {
      //statements;
   },
   _ => {
      //default
   }
};
index