比较运算 - 语法正确吗？
来自 PHP，我理解在比较操作中使用 == 和 === 的区别，但是对于 JavaScript 来说，使用 == 或 === 可以接受吗？
我想验证我的 JavaScript 代码，并找到了 JSLint。在使用 JSLint 运行验证时，我看到了这些类型的消息。
一些示例：
var show = $('input[name=female]:checked').val() == "true";
- 第 278 行第 70 行字符的问题：预期为 '!=='，但看到的是 '!='。
第 283 行第 38 行的问题
var show = $('input[name=living]:checked').val() != "false";
- ：预期为“!==”，但看到了“!=”。
所以我的问题是，使用 == 或 != 的当前语法是否有效/正确，或者我是否需要使用 === 和 !== ？
编辑：只是指出代码确实有效
Coming from PHP I understand the difference in using == verses === in a comparison operation, but with JavaScript is it acceptable to use == or ===?
I wanted to validate my JavaScript code and found JSLint. While running the validation with JSLint I see these types of messages.
Some examples:
var show = $('input[name=female]:checked').val() == "true";
- Problem at line 278 character 70: Expected '!==' and instead saw '!='.
and
var show = $('input[name=living]:checked').val() != "false";
- Problem at line 283 character 38: Expected '!==' and instead saw '!='.
So My question is, Would using the current syntax of == or != be valid/correct or do I need to use === and !== ?
EDIT: Just to point out the code does work
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评论（5）
它在某种程度上是正确的，但 JSLint 希望进行严格比较以防止类型转换出现问题。
最好只在您真正需要/想要的地方使用严格比较和“正常”比较（因为您出于某种原因想要使用类型转换）。
来自 JSLint 的 文档：
It is correct in a way but JSLint expects strict comparison to prevent problems with type conversion.
It is good practice to always use strict comparison and "normal" comparison only where you really need/want it (because you want to make use of type conversion for some reason).
From JSLint's documentation:
Crockford 和 JSLint 在这一点上有些教条，我认为过于规范。对于缺乏经验的 JavaScript 开发人员来说，始终使用
===而不是==是一个合理的经验法则，但如果您了解基本规则，那么使用就没有问题>==。特别是，如果保证两个操作数具有相同类型（例如在typeof比较中，如typeof foo == "undefined"），则这两个运算符是指定遵循完全相同的步骤。习惯性地使用
===也有一个合理的观点，即无需考虑使用哪个运算符，但坦率地说，我更喜欢被迫考虑我所使用的两个操作数的所有可能值。比较一下，发现JSLint没有必要保姆。Crockford and JSLint are somewhat dogmatic on this point, and I think over-prescriptive. Always using
===rather than==is a reasonable rule of thumb for inexperienced JavaScript developers, but if you know the basic rules then there is no problem with using==. In particular, if the two operands are guaranteed to be of the same type (such as in atypeofcomparison liketypeof foo == "undefined") then the two operators are specified to follow precisely the same steps.There is also a reasonable point about habitually using
===removing the need to think about which operator to use, but frankly I prefer to be forced to consider all the possible values of the two operands I'm comparing and find JSLint unnecessarily nannying.== 语法是有效的，但在某些情况下，它可能会导致大型项目中出现相当严重的错误。如果你没有充分的理由使用 ==，你应该默认使用 === 编写 JavaScript，因为它会检查你知道的类型。
无论哪种方式都有效，但如果你默认为===，你会在将来避免痛苦。
The == syntax is valid but in some cases it can lead to rather nasty bugs in large projects. If you don't have a good reason to use == you should by default write JavaScript with === because it checks for type as you know.
It works either way, but you will save yourself pain in the future if you default to ===.
视情况而定。
=== 通常是首选，因为您不会有任何您可能没有考虑到的误报（在某些实现中它也可能稍微快一些，因为它与较小的潜在值相比，尽管我没有检查过，只是一个认为，速度差异可以忽略不计）。
== 通常更方便地覆盖许多/所有情况（如果我没记错的话，jQuery 不会通过 JSLint，因为在某些地方，代码有意使用 == 来覆盖多种情况，而不是单独测试每个情况）。
Depends on the situation.
=== is often preferred because you won't have any false-positives that you might not have considered (it might also be slightly quicker in some implementations because it compares to less potential values, although I haven't checked that, just a thought, and the speed difference would be negligible).
== is often more convenient to cover many/all cases (if I'm not mistaken, jQuery doesn't pass JSLint because in some places the code intentionally uses == to cover a multitude of cases rather than testing each one individually).
你可以只做 == 和 != ，我认为这样做不会有任何问题。
you can do just == and !=, I don't think there would be any problems with that.