无涯教程-Tcl - 运算符运算符是一个符号，告诉编译器执行特定的数学或逻辑操作。 Tcl语言具有丰富的内置运算符，并

运算符是一个符号，告诉编译器执行特定的数学或逻辑操作。 Tcl语言具有丰富的内置运算符，并提供以下类型的运算符-

算术运算符
关系运算符
逻辑运算符
按位运算符
三元运算符

本章将逐一说明算术，关系，逻辑，按位和三元运算符。

算术运算符

下表显示了Tcl语言支持的所有算术运算符。假设变量A=10，变量 B=20，则-

Operator	Remark	Example
+	加	A + B=30
-	减	A - B=-10
*	乘	A * B=200
/	除	B/A=2
%	取模	B % A=0

#!/usr/bin/tclsh
set a 21
set b 10
set c [expr  $a </span><span class="pun">+</span><span class="pln">$ b]
puts "Line 1 - Value of c is  $c\n"</span><span class="pln"> </span><span class="kwd">set</span><span class="pln"> c </span><span class="pun">[</span><span class="pln">expr$ a -  $b</span><span class="pun">]</span><span class="pln"> puts </span><span class="str">"Line 2 - Value of c is$ c\n"
set c [expr  $a </span><span class="pun">*</span><span class="pln">$ b]
puts "Line 3 - Value of c is  $c\n"</span><span class="pln"> </span><span class="kwd">set</span><span class="pln"> c </span><span class="pun">[</span><span class="pln">expr$ a/ $b</span><span class="pun">]</span><span class="pln"> puts </span><span class="str">"Line 4 - Value of c is$ c\n"
set c [expr  $a </span><span class="pun">%</span><span class="pln">$ b]
puts "Line 5 - Value of c is $c\n"

当您编译并执行上述程序时，它将产生以下输出-

Line 1 - Value of c is 31
Line 2 - Value of c is 11
Line 3 - Value of c is 210
Line 4 - Value of c is 2
Line 5 - Value of c is 1

关系运算符

下表显示了Tcl语言支持的所有关系运算符。假设变量 A=10，变量 B=20，则-

Operator	Remark	Example
==	相等	(A == B) is not true.
!=	不相等	(A != B) is true.
>	大于	(A > B) is not true.
<	小于	(A < B) is true.
>=	大于或等于	(A >= B) is not true.
<=	小于或等于	(A <= B) is true.

尝试以下示例以了解Tcl语言中可用的所有关系运算符-

#!/usr/bin/tclsh
set a 21
set b 10
if {  $a </span><span class="pun">==</span><span class="pln">$ b } {
puts "Line 1 - a is equal to b\n"
} else {
puts "Line 1 - a is not equal to b\n"
}
if {  $a </span><span class="pun">&lt;</span><span class="pln">$ b } {
puts "Line 2 - a is less than b\n"
} else {
puts "Line 2 - a is not less than b\n"
}
if {  $a </span><span class="pun">&gt;</span><span class="pln">$ 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 {  $a </span><span class="pun">&lt;=</span><span class="pln">$ b } {
puts "Line 4 - a is either less than or equal to  b\n"
}
if {  $b </span><span class="pun">&gt;=</span><span class="pln">$ a } {
puts "Line 5 - b is either greater than  or equal to a\n"
}

当您编译并执行上述程序时，它将产生以下输出-

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

逻辑运算符

下表显示了Tcl语言支持的所有逻辑运算符。假设变量 A=1，变量 B=0，则-

Operator	Remark	Example
&&	逻辑and	(A && B) is false.
\|\|	逻辑 or	(A \|\| B) is true.
!	逻辑非	!(A && B) is true.

尝试以下示例以了解Tcl语言中可用的所有逻辑运算符-

#!/usr/bin/tclsh
set a  5
set b 20
if {  $a </span><span class="pun">&amp;&amp;</span><span class="pln">$ b } {
puts "Line 1 - Condition is true\n"
}
if {  $a </span><span class="pun">||</span><span class="pln">$ b } {
puts "Line 2 - Condition is true\n"
}
# lets change the value of  a and b 
set a  0
set b 10
if {  $a </span><span class="pun">&amp;&amp;</span><span class="pln">$ b } {
puts "Line 3 - Condition is true\n"
} else {
puts "Line 3 - Condition is not true\n"
}
if { !( $a </span><span class="pun">&amp;&amp;</span><span class="pln">$ b) } {
puts "Line 4 - Condition is true\n"
}

当您编译并执行上述程序时，它将产生以下输出-

Line 1 - Condition is true
Line 2 - Condition is true
Line 3 - Condition is not true
Line 4 - Condition is true

按位运算符

p	q	p & q	p \| q	p ^ q
0	0	0	0	0
0	1	0	1	1
1	1	1	1	0
1	0	0	1	1

假设A=60;和B=13;现在以二进制格式，它们将如下所示-

A=0011 1100
B=0000 1101
----------------------
A&B=0000 1100
A | B=0011 1101
A ^ B=0011 0001

下表列出了Tcl语言支持的按位运算符。假设变量 A 保持60，变量 B 保持13，则-

Operator	Remark	Example
&	按位 and	(A & B)=12, which is 0000 1100
\|	按位 or	(A \| B)=61, which is 0011 1101
^	按位异域	(A ^ B)=49, which is 0011 0001
<<	左移	A << 2 =240, which is 1111 0000
>>	右移	A >> 2 =15, which is 0000 1111

#!/usr/bin/tclsh
set a 60  ;# 60=0011 1100

set b 13  ;# 13=0000 1101
set c [expr  $a </span><span class="pun">&amp;</span><span class="pln">$ b] ;# 12=0000 1100
puts "Line 1 - Value of c is $c\n"
set c [expr  $a </span><span class="pun">|</span><span class="pln">$ b;] ;# 61=0011 1101
puts "Line 2 - Value of c is $c\n"
set c [expr  $a </span><span class="pun">^</span><span class="pln">$ b;] ;# 49=0011 0001
puts "Line 3 - Value of c is $c\n"
set c [expr  $a </span><span class="pun">&lt;&lt;</span><span class="pln"> </span><span class="lit">2</span><span class="pun">]</span><span class="pln"> </span><span class="pun">;#</span><span class="pln"> </span><span class="lit">240</span><span class="pun">=</span><span class="lit">1111</span><span class="pln"> </span><span class="lit">0000</span><span class="pln"> puts </span><span class="str">"Line 4 - Value of c is$ c\n"
set c [expr  $a </span><span class="pun">&gt;&gt;</span><span class="pln"> </span><span class="lit">2</span><span class="pun">]</span><span class="pln"> </span><span class="pun">;#</span><span class="pln"> </span><span class="lit">15</span><span class="pun">=</span><span class="lit">0000</span><span class="pln"> </span><span class="lit">1111</span><span class="pln"> puts </span><span class="str">"Line 5 - Value of c is$ c\n"

当您编译并执行上述程序时，它将产生以下输出-

Line 1 - Value of c is 12
Line 2 - Value of c is 61
Line 3 - Value of c is 49
Line 4 - Value of c is 240
Line 5 - Value of c is 15

三元运算符

Operator	Remark	Example
? :	三元组	如果条件为真?然后取值X:否则取值Y

尝试以下示例以了解Tcl语言中可用的三元运算符-

#!/usr/bin/tclsh
set a 10;
set b [expr  $a </span><span class="pun">==</span><span class="pln"> </span><span class="lit">1</span><span class="pln"> </span><span class="pun">?</span><span class="pln"> </span><span class="lit">20</span><span class="pun">:</span><span class="pln"> </span><span class="lit">30</span><span class="pun">]</span><span class="pln"> puts </span><span class="str">"Value of b is$ b\n"
set b [expr  $a </span><span class="pun">==</span><span class="pln"> </span><span class="lit">10</span><span class="pln"> </span><span class="pun">?</span><span class="pln"> </span><span class="lit">20</span><span class="pun">:</span><span class="pln"> </span><span class="lit">30</span><span class="pun">]</span><span class="pln"> puts </span><span class="str">"Value of b is$ b\n"

当您编译并执行上述程序时，它将产生以下输出-

Value of b is 30
Value of b is 20

Tcl优先级

运算符优先级确定表达式中术语的分组。

Category	Operator	Associativity
Unary	+ -	Right to left
Multiplicative	*/%	Left to right
Additive	+ -	Left to right
Shift	<< >>	Left to right
Relational	< <= > >=	Left to right
Bitwise AND	&	Left to right
Bitwise XOR	^	Left to right
Bitwise OR	\|	Left to right
Logical AND	&&	Left to right
Logical OR	\|\|	Left to right
Ternary	?:	Right to left

尝试以下示例以了解Tcl语言中可用的运算符优先级-

#!/usr/bin/tclsh
set a 20
set b 10
set c 15
set d 5
set  e [expr [expr  $a </span><span class="pun">+</span><span class="pln">$ b]   $c</span><span class="pun">/</span><span class="pln">$ d ]     ;# ( 30  15 )/5
puts "Value of (a + b) * c/d is : $e\n"
set  e [expr  [expr [expr  $a </span><span class="pun">+</span><span class="pln">$ b]   $c</span><span class="pun">]/</span><span class="pln">$ d]   ;#  (30  15 )/5]
puts "Value of ((a + b) * c)/d is  : $e\n"
set  e  [expr [expr  $a </span><span class="pun">+</span><span class="pln">$ b]  [expr  $c</span><span class="pun">/</span><span class="pln">$ d] ]   ;# (30)  (15/5)
puts "Value of (a + b) * (c/d) is  : $e\n"
set  e  [expr  $a </span><span class="pun">+</span><span class="pln"> </span><span class="pun">[</span><span class="pln">expr$ b *  $c </span><span class="pun">]/</span><span class="pln">$ d ] ;#  20 + (150/5)
puts "Value of a + (b * c)/d is  :  $e\n"

当您编译并执行上述程序时，它将产生以下输出-

Value of (a + b) * c/d is : 90
Value of ((a + b) * c)/d is  : 90
Value of (a + b) * (c/d) is  : 90
Value of a + (b * c)/d is  :  50

无涯教程-Tcl - 运算符

算术运算符

关系运算符

逻辑运算符

按位运算符

三元运算符

Tcl优先级

参考链接