Tcl-tk-tcl-relational-operators

Tcl-関係演算子

次の表は、Tcl言語でサポートされているすべての関係演算子を示しています。 変数 A が10を保持し、変数 B が20を保持すると仮定します-

Operator	Description	Example
==	Checks if the values of two operands are equal or not, if yes then condition becomes true.	(A == B) is not true.
!=	Checks if the values of two operands are equal or not, if values are not equal then condition becomes true.	(A != B) is true.
>	Checks if the value of left operand is greater than the value of right operand, if yes then condition becomes true.	(A > B) is not true.
<	Checks if the value of left operand is less than the value of right operand, if yes then condition becomes true.	(A < B) is true.
>=	Checks if the value of left operand is greater than or equal to the value of right operand, if yes then condition becomes true.	(A >= B) is not true.
⇐	Checks if the value of left operand is less than or equal to the value of right operand, if yes then condition becomes true.	(A ⇐ B) is true.

例

Tcl言語で利用可能なすべての関係演算子を理解するために、次の例を試してください-

#!/usr/bin/tclsh

set a 21
set b 10

if { $a == $b } {
   puts "Line 1 - a is equal to b\n"
} else {
   puts "Line 1 - a is not equal to b\n"
}
if { $a < $b } {
   puts "Line 2 - a is less than b\n"
} else {
   puts "Line 2 - a is not less than b\n"
}
if { $a > $b } {
   puts "Line 3 - a is greater than b\n"
} else {
   puts "Line 3 - a is not greater than b\n"
}
# Lets change value of a and b
set a 5
set b 20
if { $a <= $b } {
   puts "Line 4 - a is either less than or equal to  b\n"
}
if { $b >= $a } {
   puts "Line 5 - b is either greater than  or equal to a\n"
}

上記のプログラムをコンパイルして実行すると、次の結果が生成されます-

Line 1 - a is not equal to b

Line 2 - a is not less than b

Line 3 - a is greater than b

Line 4 - a is either less than or equal to  b

Line 5 - b is either greater than  or equal to a