n2实例
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实例 ryj@ubuntu:~/test/lab2$ cat 2_1_1.tcl set foo "john" puts "my name is $foo" ryj@ubuntu:~/test/lab2$ ns 2_1_1.tcl my name is john ryj@ubuntu:~/test/lab2$ cat 2_1_2.tcl set month 2 set day 3 set year 97 set date "$month:$day:$year" puts $date ryj@ubuntu:~/test/lab2$ ns 2_1_2.tcl 2:3:97 ryj@ubuntu:~/test/lab2$ cat 2_1_3.tcl set foo "puts hi" eval $foo ryj@ubuntu:~/test/lab2$ ns 2_1_3.tcl hi ryj@ubuntu:~/test/lab2$ cat 2_2_1.tcl set value [expr 0==1] puts $value ryj@ubuntu:~/test/lab2$ ns 2_2_1.tcl 0 ryj@ubuntu:~/test/lab2$ cat 2_2_2.tcl set value [expr 2>=1] puts $value ryj@ubuntu:~/test/lab2$ ns 2_2_2.tcl 1 ryj@ubuntu:~/test/lab2$ cat 2_2_3.tcl set value [expr 2+3] puts $value ryj@ubuntu:~/test/lab2$ ns 2_2_3.tcl 5 ryj@ubuntu:~/test/lab2$ cat 2_3_1.tcl puts "I am [expr 10 * 2] years old, and my I.Q. is [expr 100 - 25]" ryj@ubuntu:~/test/lab2$ ns 2_3_1.tcl I am 20 years old, and my I.Q. is 75 ryj@ubuntu:~/test/lab2$ cat 2_3_2.tcl set my_height 6.0 puts "If I was 2 inches taller, I would be [expr $my_height + (2.0 / 12.0)] feet tall" ryj@ubuntu:~/test/lab2$ ns 2_3_2.tcl If I was 2 inches taller, I would be 6.166666666666667 feet tall ryj@ubuntu:~/test/lab2$ cat 2_4_1.tcl set my_planet "earth" if {$my_planet == "earth"} { puts "I feel right at home." } elseif {$my_planet == "venus"} { puts "This is not my home." } else { puts "I am neither from Earth, nor from Venus." } set temp 95 if {$temp < 80} { puts "It's a little chilly." } else { puts "Warm enough for me." } ryj@ubuntu:~/test/lab2$ ns 2_4_1.tcl I feel right at home. Warm enough for me. ryj@ubuntu:~/test/lab2$ cat 2_4_2.tcl set num_legs 6 switch $num_legs { 2 {puts "It could be a human."} 1 / 3 4 {puts "It could be a cow."} 6 {puts "It could be an ant."} 8 {puts "It could be a spider."} default {puts "It could be anything."} } ryj@ubuntu:~/test/lab2$ ns 2_4_2.tcl It could be an ant. ryj@ubuntu:~/test/lab2$ cat 2_4_3.tcl for {set i 0} {$i < 5} {incr i 1} { puts "In the for loop, and i == $i" } ryj@ubuntu:~/test/lab2$ ns 2_4_3.tcl In the for loop, and i == 0 In the for loop, and i == 1 In the for loop, and i == 2 In the for loop, and i == 3 In the for loop, and i == 4 ryj@ubuntu:~/test/lab2$ cat 2_4_4.tcl set i 0 while {$i < 5} { puts "In the while loop, and i == $i" incr i 1 } ryj@ubuntu:~/test/lab2$ ns 2_4_4.tcl In the while loop, and i == 0 In the while loop, and i == 1 In the while loop, and i == 2 In the while loop, and i == 3 In the while loop, and i == 4 ryj@ubuntu:~/test/lab2$ cat 2_4_5.tcl foreach vowel {a e i o u} { puts "$vowel is a vowel" } ryj@ubuntu:~/test/lab2$ ns 2_4_5.tcl a is a vowel e is a vowel i is a vowel o is a vowel u is a vowel ryj@ubuntu:~/test/lab2$ cat 2_5_1.tcl proc sum_proc {a b} { return [expr $a + $b] } proc magnitude {num} { if {$num > 0} { return $num } set num [expr $num * (-1)] return $num } set num1 12 set num2 14 set sum [sum_proc $num1 $num2] puts "The sum is $sum" puts "The magnitude of 3 is [magnitude 3]" puts "The magnitude of -2 is [magnitude -2]" ryj@ubuntu:~/test/lab2$ ns 2_5_1.tcl The sum is 26 The magnitude of 3 is 3 The magnitude of -2 is 2 ryj@ubuntu:~/test/lab2$ cat 2_5_2.tcl proc dumb_proc {} { set myvar 4 puts "The value of the local variable is $myvar" global myglobalvar puts "The value of the global variable is $myglobalvar" } set myglobalvar 79 dumb_proc 2 / 3 ryj@ubuntu:~/test/lab2$ ns 2_5_2.tcl The value of the local variable is 4 The value of the global variable is 79 ryj@ubuntu:~/test/lab2$ cat 2_6_1.tcl set myarray(0) "Zero" set myarray(1) "One" set myarray(2) "Two" for {set i 0} {$i < 3} {incr i 1} { puts $myarray($i) } ryj@ubuntu:~/test/lab2$ ns 2_6_1.tcl Zero One Two ryj@ubuntu:~/test/lab2$ cat 2_6_2.tcl set person_info(name) "Fred Smith" set person_info(age) "25" set person_info(occupation) "Plumber" foreach thing {name age occupation} { puts "$thing == $person_info($thing)" } ryj@ubuntu:~/test/lab2$ ns 2_6_2.tcl name == Fred Smith age == 25 occupation == Plumber ryj@ubuntu:~/test/lab2$ cat 2_6_3.tcl set person_info(name) "Fred Smith" set person_info(age) "25" set person_info(occupation) "Plumber" foreach thing [array names person_info] { puts "$thing == $person_info($thing)" } ryj@ubuntu:~/test/lab2$ ns 2_6_3.tcl occupation == Plumber age == 25 name == Fred Smith ryj@ubuntu:~/test/lab2$ cat 2_7_1.tcl set str "This is a string" puts "The string is: $str" puts "The length of the string is: [string length $str]" puts "The character at index 2 is: [string index $str 2]" puts "The characters from index 4 through 8 are: [string range $str 4 8]" puts "The index of the first occurrence of letter \"i\" is: [string first i $str]" ryj@ubuntu:~/test/lab2$ ns 2_7_1.tcl The string is: This is a string The length of the string is: 16 The character at index 2 is: i The characters from index 4 through 8 are: is a The index of the first occurrence of letter "i" is: 2 ryj@ubuntu:~/test/lab2$ cat 2_8_1.tcl set f [open "/tmp/myfile" "w"] puts $f "We live in Texas. It's already 110 degrees out here." puts $f "456" close $f ryj@ubuntu:~/test/lab2$ ns 2_8_1.tcl 3 / 3 本文来源：https://www.wddqw.com/doc/866cf8f8770bf78a6529544e.html