if 语句后可以跟可选的 elsif ... else 语句,这对于使用单个if ... elsif语句测试各种条件非常有用。
if...elsif...else - 语法
Perl编程语言中的 if ... elsif...else语句的语法是-
if(boolean_expression 1) {# Executes when the boolean expression 1 is true } elsif( boolean_expression 2) {# Executes when the boolean expression 2 is true } elsif( boolean_expression 3) {# Executes when the boolean expression 3 is true } else {# Executes when the none of the above condition is true }
if...elsif...else - 示例
#!/usr/local/bin/perl$a=100; # check the boolean condition using if statement if( $a == 20 ) {# if condition is true then print the followingprintf "a has a value which is 20\n"; } elsif( $a == 30 ) {# if condition is true then print the followingprintf "a has a value which is 30\n"; } else {# if none of the above conditions is trueprintf "a has a value which is $a\n"; }
在这里,我们使用等于运算符==,用于检查两个操作数是否相等。如果两个操作数相同,则返回true,否则返回false。
a has a value which is 100
Perl 中的 if...elsif...else语句函数 - 无涯教程网无涯教程网提供if 语句后可以跟可选的 elsif ... else 语句,这对于使用单个if ... elsif 语句测试各...https://www.learnfk.com/perl/perl-if-elsif-statement.html