R 简明教程

R - Decision making

决策结构要求程序员指定程序要评估或测试的一个或多个条件，以及在确定条件为 true 时要执行的语句或语句，而且在条件确定为 false 时可能还要执行其他一些语句。

Decision making structures require the programmer to specify one or more conditions to be evaluated or tested by the program, along with a statement or statements to be executed if the condition is determined to be true, and optionally, other statements to be executed if the condition is determined to be false.

以下是大多数编程语言中常见的典型决策结构的一般形式 −

Following is the general form of a typical decision making structure found in most of the programming languages −

r decision making

R 提供以下类型的决策语句。单击以下链接查看其详细信息。

R provides the following types of decision making statements. Click the following links to check their detail.

Sr.No.

Statement & Description

1

if statementAn if statement consists of a Boolean expression followed by one or more statements.

2

if…​else statementAn if statement can be followed by an optional else statement, which executes when the Boolean expression is false.

3

switch statementA switch statement allows a variable to be tested for equality against a list of values.