下表列出了所有Tcl語(yǔ)言支持的邏輯運(yùn)算符。假設(shè)變量A=1和變量B=0,則:
| 運(yùn)算符 | 描述 | 例子 |
|---|---|---|
| && | 所謂邏輯與運(yùn)算符。如果兩個(gè)操作數(shù)都非零,則條件變?yōu)檎妗?/td> | (A && B) 為 false. |
| || | 所謂的邏輯或操作。如果任何兩個(gè)操作數(shù)是非零,則條件變?yōu)檎妗?/td> | (A || B) 為 true. |
| ! | 所謂邏輯非運(yùn)算符。使用反轉(zhuǎn)操作數(shù)的邏輯狀態(tài)。如果條件為真,那么邏輯非運(yùn)算符為假。 | !(A && B) 為 true. |
試試下面的例子就明白了所有Tcl語(yǔ)言提供的邏輯運(yùn)算符:
#!/usr/bin/tclsh
set a 5
set b 20
if { $a && $b } {
puts "Line 1 - Condition is true\n"
}
if { $a || $b } {
puts "Line 2 - Condition is true\n"
}
# lets change the value of a and b
set a 0
set b 10
if { $a && $b } {
puts "Line 3 - Condition is true\n"
} else {
puts "Line 3 - Condition is not true\n"
}
if { !($a && $b) } {
puts "Line 4 - Condition is true\n"
}
當(dāng)編譯和執(zhí)行上面的程序,會(huì)產(chǎn)生以下結(jié)果:
Line 1 - Condition is true Line 2 - Condition is true Line 3 - Condition is not true Line 4 - Condition is true