[英]Converting String to "Character" array in Java
I want to convert a String
to an array of objects of Character class but I am unable to perform the conversion.我想将String
转换为Character class 的对象数组,但我无法执行转换。 I know that I can convert a String to an array of primitive datatype type "char" with the toCharArray()
method but it doesn't help in converting a String to an array of objects of Character type.我知道我可以使用toCharArray()
方法将 String 转换为原始数据类型“char”的数组,但它无助于将 String 转换为Character类型的对象数组。
How would I go about doing so?请问我go怎么办呢?
Use this:用这个:
String str = "testString";
char[] charArray = str.toCharArray();
Character[] charObjectArray = ArrayUtils.toObject(charArray);
One liner with java-8 :一个带java-8的班轮:
String str = "testString";
//[t, e, s, t, S, t, r, i, n, g]
Character[] charObjectArray =
str.chars().mapToObj(c -> (char)c).toArray(Character[]::new);
What it does is:它的作用是:
IntStream
of the characters (you may want to also look at codePoints()
)获取字符的IntStream
(您可能还想查看codePoints()
)Character
(you need to cast to actually say that its really a char
, and then Java will box it automatically to Character
) map 将每个“字符”值转换为Character
(您需要强制转换以实际说明它确实是一个char
,然后 Java 会自动将其装箱为Character
)toArray()
通过调用toArray()
获取结果数组Why not write a little method yourself为什么不自己写一个小方法
public Character[] toCharacterArray( String s ) {
if ( s == null ) {
return null;
}
int len = s.length();
Character[] array = new Character[len];
for (int i = 0; i < len ; i++) {
/*
Character(char) is deprecated since Java SE 9 & JDK 9
Link: https://docs.oracle.com/javase/9/docs/api/java/lang/Character.html
array[i] = new Character(s.charAt(i));
*/
array[i] = s.charAt(i);
}
return array;
}
Converting String to Character Array and then Converting Character array back to String将字符串转换为字符数组,然后将字符数组转换回字符串
//Givent String
String given = "asdcbsdcagfsdbgdfanfghbsfdab";
//Converting String to Character Array(It's an inbuild method of a String)
char[] characterArray = given.toCharArray();
//returns = [a, s, d, c, b, s, d, c, a, g, f, s, d, b, g, d, f, a, n, f, g, h, b, s, f, d, a, b]
//ONE WAY: Converting back Character array to String //一种方法:将字符数组转换回字符串
int length = Arrays.toString(characterArray).replaceAll("[, ]","").length();
//First Way to get the string back
Arrays.toString(characterArray).replaceAll("[, ]","").substring(1,length-1)
//returns asdcbsdcagfsdbgdfanfghbsfdab
or
// Second way to get the string back
Arrays.toString(characterArray).replaceAll("[, ]","").replace("[","").replace("]",""))
//returns asdcbsdcagfsdbgdfanfghbsfdab
//Second WAY: Converting back Character array to String //第二种方式:将字符数组转换回字符串
String.valueOf(characterArray);
//Third WAY: Converting back Character array to String //第三种方式:将字符数组转换回字符串
Arrays.stream(characterArray)
.mapToObj(i -> (char)i)
.collect(Collectors.joining());
Converting string to Character Array将字符串转换为字符数组
Character[] charObjectArray =
givenString.chars().
mapToObj(c -> (char)c).
toArray(Character[]::new);
Converting char array to Character Array将字符数组转换为字符数组
String givenString = "MyNameIsArpan";
char[] givenchararray = givenString.toCharArray();
String.valueOf(givenchararray).chars().mapToObj(c ->
(char)c).toArray(Character[]::new);
benefits of Converting char Array to Character Array you can use the Arrays.stream funtion to get the sub array将字符数组转换为字符数组的好处您可以使用 Arrays.stream 函数获取子数组
String subStringFromCharacterArray =
Arrays.stream(charObjectArray,2,6).
map(String::valueOf).
collect(Collectors.joining());
You have to write your own method in this case.在这种情况下,您必须编写自己的方法。 Use a loop and get each character using charAt(i)
and set it to your Character[]
array using arrayname[i] = string.charAt[i]
.使用循环并使用charAt(i)
获取每个字符,并使用arrayname[i] = string.charAt[i]
将其设置为您的Character[]
数组。
String#toCharArray
returns an array of char
, what you have is an array of Character
. String#toCharArray
返回一个char
数组,你拥有的是一个Character
数组。 In most cases it doesn't matter if you use char
or Character
as there is autoboxing .在大多数情况下,使用char
或Character
并不重要,因为有autoboxing 。 The problem in your case is that arrays are not autoboxed, I suggest you use an array of char ( char[]
).你的问题是 arrays 没有自动装箱,我建议你使用一个 char 数组( char[]
)。
I hope the code below will help you.我希望下面的代码对您有所帮助。
String s="Welcome to Java Programming";
char arr[]=s.toCharArray();
for(int i=0;i<arr.length;i++){
System.out.println("Data at ["+i+"]="+arr[i]);
}
It's working and the output is:它正在工作,output 是:
Data at [0]=W
Data at [1]=e
Data at [2]=l
Data at [3]=c
Data at [4]=o
Data at [5]=m
Data at [6]=e
Data at [7]=
Data at [8]=t
Data at [9]=o
Data at [10]=
Data at [11]=J
Data at [12]=a
Data at [13]=v
Data at [14]=a
Data at [15]=
Data at [16]=P
Data at [17]=r
Data at [18]=o
Data at [19]=g
Data at [20]=r
Data at [21]=a
Data at [22]=m
Data at [23]=m
Data at [24]=i
Data at [25]=n
Data at [26]=g
another way to do it.另一种方法来做到这一点。
String str="I am a good boy";
char[] chars=str.toCharArray();
Character[] characters=new Character[chars.length];
for (int i = 0; i < chars.length; i++) {
characters[i]=chars[i];
System.out.println(chars[i]);
}
This method take String as a argument and return the Character Array此方法以字符串为参数并返回字符数组
/**
* @param sourceString
* :String as argument
* @return CharcterArray
*/
public static Character[] toCharacterArray(String sourceString) {
char[] charArrays = new char[sourceString.length()];
charArrays = sourceString.toCharArray();
Character[] characterArray = new Character[charArrays.length];
for (int i = 0; i < charArrays.length; i++) {
characterArray[i] = charArrays[i];
}
return characterArray;
}
if you are working with JTextField then it can be helpfull..如果您正在使用 JTextField 那么它可能会有所帮助..
public JTextField display;
String number=e.getActionCommand();
display.setText(display.getText()+number);
ch=number.toCharArray();
for( int i=0; i<ch.length; i++)
System.out.println("in array a1= "+ch[i]);
chaining is always best:D链接总是最好的:D
String str = "somethingPutHere";
Character[] c = ArrayUtils.toObject(str.toCharArray());
If you don't want to rely on third party API's, here is a working code for JDK7 or below.如果您不想依赖第三方 API,这里是 JDK7 或更低版本的工作代码。 I am not instantiating temporary Character Objects as done by other solutions above.我没有像上面其他解决方案那样实例化临时角色对象。 foreach loops are more readable, see yourself:) foreach 循环更具可读性,看你自己:)
public static Character[] convertStringToCharacterArray(String str) {
if (str == null || str.isEmpty()) {
return null;
}
char[] c = str.toCharArray();
final int len = c.length;
int counter = 0;
final Character[] result = new Character[len];
while (len > counter) {
for (char ch : c) {
result[counter++] = ch;
}
}
return result;
}
I used the StringReader class in java.io .我在 java.io 中使用了StringReader class 。 One of it's functions read(char[] cbuf)
reads a string's contents into an array.其中一个函数read(char[] cbuf)
将字符串的内容读入数组。
String str = "hello";
char[] array = new char[str.length()];
StringReader read = new StringReader(str);
try {
read.read(array); //Reads string into the array. Throws IOException
} catch (IOException e) {
e.printStackTrace();
}
for (int i = 0; i < str.length(); i++) {
System.out.println("array["+i+"] = "+array[i]);
}
Running this gives you the output:运行它会得到 output:
array[0] = h
array[1] = e
array[2] = l
array[3] = l
array[4] = o
String[] arr = { "abc", "cba", "dac", "cda" };
Map<Character, Integer> map = new HashMap<>();
String string = new String();
for (String a : arr) {
string = string.concat(a);
}
System.out.println(string);
for (int i = 0; i < string.length(); i++) {
if (map.containsKey(string.charAt(i))) {
map.put(string.charAt(i), map.get(string.charAt(i)) + 1);
} else {
map.put(string.charAt(i), 1);
}
}
System.out.println(map);
//out put {a=4, b=2, c=4, d=2} //输出 {a=4, b=2, c=4, d=2}
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.