我正在编辑某人的代码 s 代码, 我不明白他们想用这个语句做什么。 这是在函数的结尾处 。
return !(this.variable == "value")
它们返回 true 或 false 或 , 其依据与比较结果相反。
写:
return this.variable != "value";
有时你看:
return !!(some.expression);
强制将表达式结果“ 真实性” 转换为布林( true 或 false ) 。 “!!! > 仅仅是一对单个逻辑补充(“ 不 ” ) 运算符。 第一个( 右) 将表达式结果转换为布林, 但与“ 真实性” 相对。 因此, 第二个( 右) 将它翻回 。
this.variable == "value"
将两个值与布尔比较, 并进行比对( 如果比对相同的话) 。
!(this.variable == "value")
这将否定值( 真正的 & lt;- & gt; 假的) 。
return !(this.variable == "value")
这返回函数中的值。
他们正在检查此值。 可变性等于“ 值”( 它返回真实或虚假), 然后使用! (不是) 来使值相反 。
取得与
return (this.variable != "value")
你还是改成这样吧 因为它更清楚多了
它正在返回一个真实的或虚假的...
感叹点不是...
所以,这个变量不等于“值”。
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