scala字符串的拉链操作_在Scala中对字符串进行操作

scala字符串的拉链操作

Scala字符串操作 (Scala strings operation)

A string is a very important datatype in Scala. This is why there are a lot of operations that can be done on the string object. Since the regular operations like addition, subtraction is not valid for a string, therefore, special operations like concatenation, comparison are defined.

字符串是Scala中非常重要的数据类型。这就是为什么可以对字符串对象执行许多操作的原因。由于常规操作(如加法，减法)对于字符串无效，因此，定义了特殊操作(如串联，比较)。

In this tutorial, we will share some of the important and common string functions.

在本教程中，我们将分享一些重要和通用的字符串函数 。

1)字符串相等(==) (1) String Equality (==))

The tradition equality operator == is also available in the string. You can use it to find equality of two string and the equality results in a boolean value.

字符串中也可以使用传统的等于运算符== 。您可以使用它来查找两个字符串的相等性，并且相等性会产生布尔值。

    str1 = str2 // this will return either TRUE OR FALSE

For Example,

例如，

    val str1 = "Include"
val str2 = "Includes"
str1 == str2 // this will be false

2)字符串长度 (2) String Length)

There is an inbuilt function that is used to find the number of characters in a string. It includes all the space that comes it between. It is used to set the limit for string traversal.

有一个内置函数，用于查找字符串中的字符数。它包括介于两者之间的所有空间。用于设置字符串遍历的限制。

    // this outputs a positive integer denoting the // number of characters in the array. str1.length

For example,

例如，

    val str1 = "Include help"
str1.length // this will print 12

3)串连音 (3) String concat)

You can concatenate a string on other. It means the string will be appended on the calling string.

您可以在其他字符串上串联一个字符串。这意味着该字符串将附加在调用字符串上。

    str1.concat(str2)

for example,

例如，

    val str1 = "Include"
val str2 = "Help"
str1.concat(str2) // This will print IncludeHelp

4)字符串charAt()方法 (4) String charAt() method )

To print the character at a specific index of the string the charAt method is used. The input is a zero-based index and output will be the corresponding character. Will throw an error if the input is greater than the length of the string.

要在字符串的特定索引处打印字符，请使用charAt方法。输入是从零开始的索引，输出将是相应的字符。如果输入大于字符串的长度，将引发错误。

    str1.charAt(n)

For example,

例如，

    val name = "Include"
name.charAt(4) // This will output u.

5)indexOf()方法 (5) indexOf() method)

The indexOf() method is used to check the index of a character in a string. This method returns an integer which is positive within the length of the string when the character is found in the array otherwise -1 is given as output.

indexOf()方法用于检查字符串中字符的索引。当在数组中找到字符时，此方法返回一个整数，该整数在字符串的长度内为正，否则将给出-1作为输出。

    str1.indexOf("a")

For example,

例如，

    val name = "Include"
name.indexOf("d") // This will output 5.

6)Substring()方法 (6) Substring() method)

The substring method is used to define a substring from the calling string. It makes a new string with the specified part of the string.

substring方法用于从调用字符串中定义一个子字符串。它使用字符串的指定部分创建一个新字符串。

    str2 =  str1.substring(startIndex , endIndex)

For example,

例如，

    val name = "IncludeHelp is awesome"
name.substring(14 , 21) // This will output awesome.

Example code that uses all these functions

使用所有这些功能的示例代码

object MyClass {
def main(args: Array[String]) {
val str1 = "include Help "
val str2 = "is awesome"
println("str1 = " + str1)
println("str2 = " + str2)
println("Comparison between str1 and str2 is " + (str1 == str2))
println("The length of str1 is " + str1.length)
println("Concatenating str1 with str2 gives \n " + str1.concat(str2))
println("The character at  index 5 of str2 is" + str2.charAt(5))
println("The index of 'c' in str1 is " + str1.indexOf("c"))
}
}

Output

输出量

str1 = include Help 
str2 = is awesome
Comparison between str1 and str2 is false
The length of str1 is 13
Concatenating str1 with str2 gives include Help is awesome
The character at  index 5 of str2 ise
The index of 'c' in str1 is 2