java string查找_查找输出程序（Java String类）

java string查找

Program 1

程序1

public class iHelp
{
public static void main (String[] args)
{
System.out.println("Google".charAt(3));
}
}

Output

输出量

Explanation

说明

String.charAt() is a library function of String class, it returns character from given index of the string. Here, in the statement "Google".charAt(3) will return 'g', because 'g' exists on the 3^rd index.

String.charAt()是String类的库函数，它从字符串的给定索引返回字符。此处，在语句“ Google”中，charAt(3)将返回'g' ，因为'g'存在于^第三个索引上。

Program 2

程序2

public class iHelp
{
public static void main (String[] args)
{
System.out.println("Google"+3);
}
}

Output

输出量

    Google3

Explanation

说明

In java String, "+" is a concatenation operator, if we concatenate any number or string with the string, it returns that number/string concatenated to the string.

在java字符串中， “ +”是连接运算符，如果我们将任何数字或字符串与字符串连接，它将返回连接到该字符串的数字/字符串。

Here, "Google" is a string and 3 is a number. The resultant string of "Google"+3 will be "Google3".

在这里， “ Google”是一个字符串，而3是一个数字。结果字符串“ Google” +3将为“ Google3” 。

Program 3

程序3

public class iHelp
{
public static void main (String[] args)
{
System.out.println(10+20);
}
}

Output

输出量

Explanation

说明

10+20 is a simple numeric expression, addition will be performed. Therefore, the result will be 30.

10 + 20是一个简单的数字表达式，将执行加法运算。因此，结果将是30 。

Program 4

程序4

public class iHelp
{
public static void main (String[] args)
{
if(System.out.println(10) == System.out.println(10))
System.out.println("TRUE");
else
System.out.println("FALSE");
}
}

Output

输出量

Compilation error:

编译错误：

    Main.java:6: error: 'void' type not allowed here
if(System.out.println(10) == System.out.println(10))
^
1 error

Explanation

说明

The statement System.out.println() does not return anything. Therefore, no value will be for compression. Error will be "void" type not allowed here.

语句System.out.println()不返回任何内容。因此，没有任何压缩值。错误将是此处不允许的“ void”类型 。

Program 5

程序5

public class iHelp
{
public static void main (String[] args)
{
System.out.println(10+20+""+40);
}
}

Output

输出量

Explanation

说明

10+20 will be added first, and result of 10+20 will be 30. Then, " " will be concatenated to the 30, so it will become "30" in string. After that, "30"+40 will be "3040" (because if any string/number is added to the string it will concatenate as string).

10 + 20将被首先添加，以及10 + 20的结果将是30。然后，“”将被级联到30，所以它会成为“字符串30”。 此后， “ 30” +40将为“ 3040” (因为如果在字符串中添加了任何字符串/数字，它将串联为字符串)。

Therefore, output will be "3040".

因此，输出将为“ 3040” 。