为什么groovy map关键评估在使用GStrings的类似情况下表现不同? [英] Why does groovy map key evaluation behave differently in similar circumstances when using GStrings?
问题描述
def t =test
我很感谢有人向我解释为什么会出现下列情况: assert [test:1] == [test:1] // 1. expected
assert [$ t:1]!= [test:1] // 2. unexpected>
assert [$ t:1]!= [test:1] // 3.意外的
assert [$ t:1] == [$ t:1] // 4. expected
println [$ t:1] //输出:[test:1]
println [test:1] //输出:[test:1]
我不明白为什么结果#2和#3有不等式。
我写了一个测试,在代码中动态创建密钥时遇到了这个问题,但考虑到测试条件,我知道它应该是字符串test。问题是返回的出现是正确的,但并不相同。我不明白为什么。
此外,以下作品:
def t =test
def odd = [$ t:1]
assert!odd [$ t]
assert!odd.test
assert!odd [test]
assert!odd。$ t
println odd //输出:[test:1]
def d = new Date ()
def t2 =$ t
def odd2 = [(t2):1,(d):2]
assert odd2 [d] == 2
assert !odd2 [d.toString()]
assert!odd2 [t2] //预计1
odd2.put(t2,3)
println odd2 //输出:[test:3, / * date#toString * /:2]
assert odd.getAt(d)== 2
assert!odd2.getAt(t2)// expected 3
添加这两行
assert$ t.class.simpleName =='GStringImpl'
assert t.class.simpleName =='String'
或者只是
println$ t.class
println t.class
after t他的第一句话,你将能够理解为什么。 :)
如果你真的想要使用 t
的值,那么你应该使用as:
assert [(t):1] == [test:1] //使用(t)将变量值用作键
assert [(t):1] == [test:1]
assert [(t):1]!= [$ t:1]
更新
<$ c $因此鼓励使用(t)而不是GStringImpl
def odd = [($ t.toString()):1]
声明奇数[$ t]
assert odd.test
assert odd [test]
声明奇数。$ t
//通过引用和按照Groovy中的值
assert$ t==test// Value Equality ==在Groovy中重写
assert!$ t.is(test)// Object Reference equal equivalent to Java in Java
I would appreciate someone explaining to me why the following is true:
def t = "test"
assert [test: 1] == ["test": 1] // 1. expected
assert ["$t": 1] != ["test": 1] // 2. unexpected
assert ["$t": 1] != [test: 1] // 3. unexpected
assert ["$t": 1] == ["$t": 1] // 4. expected
println ["$t": 1] // output: [test: 1]
println ["test": 1] // output: [test: 1]
I don't understand why there is the inequality for results #2 and #3.
I ran into this in writing a test where the key get dynamically created in the code, but given the test conditions I know it should be the string "test". The problem is that the returned "appears" correct but is not considered equal. And I don't understand why.
Further, the following "works":
def t = "test"
def odd = ["$t": 1]
assert !odd["$t"]
assert !odd.test
assert !odd["test"]
assert !odd."$t"
println odd // output: [test: 1]
def d = new Date()
def t2 = "$t"
def odd2 = [(t2): 1, (d): 2]
assert odd2[d] == 2
assert !odd2[d.toString()]
assert !odd2[t2] // expected 1
odd2.put(t2, 3)
println odd2 // output: [test: 3, /* date#toString */: 2]
assert odd.getAt(d) == 2
assert !odd2.getAt(t2) // expected 3
Add these 2 lines
assert "$t".class.simpleName == 'GStringImpl'
assert t.class.simpleName == 'String'
or just
println "$t".class
println t.class
after the first line, you will be able to understand why. :)
If you actually want to use the value of t
then you should use as:
assert [(t): 1] == ["test": 1] //use (t) to use the variable value as key
assert [(t): 1] == [test: 1]
assert [(t): 1] != ["$t": 1]
UPDATE
//String key as before, hence encouraged to use (t) instead of GStringImpl
def odd = [("$t".toString()): 1]
assert odd["$t"]
assert odd.test
assert odd["test"]
assert odd."$t"
//Equality by reference and by value in Groovy
assert "$t" == "test" //Value Equality == overridden in Groovy
assert !"$t".is("test") //Object Reference equality equivalent to == in Java
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