blocks|key|895148|text|int是一种基本类型。String是类的。按照惯例，Java类名以大写字母开头。原语类型都是小写(Java中只定义了几个原语类型)。这只是命名类型的方式。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|895149|entityMap^0|0|3|B|6|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]|$9|K|A|L|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|M|8|@]|D|@]|E|$]]]|G|$]]

<code>int</code> is a primitive type. <code>String</code> is class. By convention, Java class names start with an uppercase. Primitive types are all lowercase (there are only a few primitive types defined in Java). It's just the way types are named.

blocks|key|638951|text|因为Java区分大小写，类是String，而不是string。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|638952|试试Int+y+=+4;，这也不管用。|638953|像int这样的原始数据类型都以小写开头，String不是原始数据类型，因此是大写的。|638954|entityMap^0|E|6|O|6|0|2|A|0|1|3|K|6|0^^$0|@$1|2|3|4|5|6|7|L|8|@$9|M|A|N|B|C]|$9|O|A|P|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|Q|8|@$9|R|A|S|B|C]]|D|@]|E|$]]|$1|H|3|I|5|6|7|T|8|@$9|U|A|V|B|C]|$9|W|A|X|B|C]]|D|@]|E|$]]|$1|J|3|-4|5|6|7|Y|8|@]|D|@]|E|$]]]|K|$]]

Because Java is case sensitive and the class is <code>String</code>, not <code>string</code>.

Try <code>Int y = 4;</code>, that won't work either.

Primitive data types like <code>int</code> all start with lowercase, <code>String</code> isn't a primitive data type and thus is capitalized.

blocks|key|895128|text|java中的integer既不是关键字，也不是类名。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|895129|string也不是。|895130|Integer是一个类名(整数变量的包装类)。|895131|int是一个关键字(指示整数基元数据类型)。|895132|String是一个类名。|895133|entityMap^0|6|7|0|0|6|0|0|7|0|0|3|0|0|6|0^^$0|@$1|2|3|4|5|6|7|P|8|@$9|Q|A|R|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|S|8|@$9|T|A|U|B|C]]|D|@]|E|$]]|$1|H|3|I|5|6|7|V|8|@$9|W|A|X|B|C]]|D|@]|E|$]]|$1|J|3|K|5|6|7|Y|8|@$9|Z|A|10|B|C]]|D|@]|E|$]]|$1|L|3|M|5|6|7|11|8|@$9|12|A|13|B|C]]|D|@]|E|$]]|$1|N|3|-4|5|6|7|14|8|@]|D|@]|E|$]]]|O|$]]

<code>integer</code> in java is not a keyword nor a class name.

<code>string</code> neither.

<code>Integer</code> is a class name (wrapper class for integer variable).

<code>int</code> is a keyword (indicates an integer primitive data type).

<code>String</code> is a class name.

blocks|key|638966|text|Hi:原语类型由语言预定义，并由保留关键字命名。基元值不与其他原语值共享状态。String类在技术上不是一个原始数据类型，它包含了Java+(您可以更多地了解它，总是有用的！)因此，int和String最大的区别是，一个是Java类，另一个不是Java类。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|638967|这是Java中所有原语的列表(都是小写的)：|638968|数字原语：short,+int,+long,+float+&+double.文本原语：byte+and+char.布尔和空原语：boolean+and+null.|offset|length|style|CODE|638969|对于Java类，您可以检查另一个post+->|638970|Most-interest-classes|638971|最后，你可以看到另一个不同之处，我记得这个：|638972|如果您想要一个ints列表，则必须键入以下列表：|638973|List<Integer>+myInts+=+new+ArrayList<Integer>();
myInts.add(1);
myInts.add(2);.......|code-block|syntax|javascript|638974|希望它能帮到你。|638975|entityMap|0|LINK|mutability|MUTABLE|url|https://stackoverflow.com/questions/3327451/most-interesting-useful-java-classes^0|0|0|5|X|17|E|1S|H|0|0|0|L|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|16|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|17|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|18|8|@$F|19|G|1A|H|I]|$F|1B|G|1C|H|I]|$F|1D|G|1E|H|I]]|9|@]|A|$]]|$1|J|3|K|5|6|7|1F|8|@]|9|@]|A|$]]|$1|L|3|M|5|6|7|1G|8|@]|9|@$F|1H|G|1I|1|1J]]|A|$]]|$1|N|3|O|5|6|7|1K|8|@]|9|@]|A|$]]|$1|P|3|Q|5|6|7|1L|8|@]|9|@]|A|$]]|$1|R|3|S|5|T|7|1M|8|@]|9|@]|A|$U|V]]|$1|W|3|X|5|6|7|1N|8|@]|9|@]|A|$]]|$1|Y|3|-4|5|6|7|1O|8|@]|9|@]|A|$]]]|Z|$10|$5|11|12|13|A|$14|15]]]]

Hi: a primitive type is predefined by the language and is named by a reserved keyword. Primitive values do not share state with other primitive values. 
 The String class is not technically a primitive data type, it is included Java API (You can read a little more about it, always useful!).
 So, the biggest difference between int and String, is only that one is a Java Class, and the other is not.

this is a list of all the primitives in Java (all in lower case):

Numeric primitives: <code>short, int, long, float &amp; double.</code>
Textual primitives: <code>byte and char.</code>
Boolean and null primitives: <code>boolean and null.</code>

For the Java Api Classes, you can check this other post ->

<a href="https://stackoverflow.com/questions/3327451/most-interesting-useful-java-classes">Most-interest-classes</a>

Finally, you can see another difference, I remember this one:

If you want a list of ints, you MUST type the list like this:

<pre><code>List&lt;Integer&gt; myInts = new ArrayList&lt;Integer&gt;();
myInts.add(1);
myInts.add(2);.......
</code></pre>

I hope it helps you.

blocks|key|1363479|text|因为它是一个预定义的类，使类的第一个字母仅以大写字母表示是一种常见的编程风格。而且所有的原始数据类型(如short,char,int,byte,float,double,long,boolean)编程风格都是使第一个字母变小。它在java中是默认的。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1363480|entityMap^0|1G|19|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|K|8|@]|D|@]|E|$]]]|G|$]]

Because it is a predefined class, and it is a common programming style to make the first letter of a class in uppercase only. And all primitive datatypes (like <code>short,char,int,byte,float,double,long,boolean</code>) programming style is to make first letter as small. It is default in java

I am inquiring about data types in Java.

<pre><code>public class Example {

 public static void main(String[] args) {

 string x = "String variable";

 int y = 4;

 System.out.println(x);
 System.out.println(y); 
 }
}
</code></pre>

Why do I receive an error when I declare a <code>string</code> variable as all lowercase? I can declare <code>integers</code> and other data types all lowercase, but when I declare a <code>string</code> variable I must capitalize the "s" in "string"?

Java data types

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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我正在询问Java中的数据类型。public class Example {    public static void main(String[] args) {        string x = "String variable";        int y = 4;        System.out.println(x);        System.out.println(y);   

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