This example will show you three methods that can convert a Java char array to a Java String object. Each method has it’s unique advantage and disadvantages. Please see the code comments for detail introduction.
public class ConvertCharArrayToString {
public static void main(String[] args) {
/* Declare an array. */
char chaArrObj[] = {'i',' ','l','o','v','e',' ','j','a','v','a'};
ConvertCharArrayToString.charArrryToString1(chaArrObj);
ConvertCharArrayToString.charArrryToString2(chaArrObj);
ConvertCharArrayToString.charArrryToString3(chaArrObj);
}
/* Use constructor to create directly from the array.*/
public static String charArrryToString1(char chaArr[])
{
String retStr = new String(chaArr);
System.out.println(retStr);
return retStr;
}
/* Use StringBuffer. */
public static String charArrryToString2(char chaArr[])
{
/* Declare a StringBuffer obect.*/
StringBuffer strBuf = new StringBuffer();
if(chaArr!=null)
{
/* Loop in the array, append each char to the StringBuffer object.
Because only one StringBuffer object is created, so this method will cost less. */
int len = chaArr.length;
for(int i=0;i<len;i++)
{
char cha = chaArr[i];
strBuf.append(cha);
}
}
/* Translate strBuf object to retStrObj.*/
String retStrObj = strBuf.toString();
System.out.println(retStrObj);
return retStrObj;
}
/* Use "+" operator. */
public static String charArrryToString3(char chaArr[])
{
/* Declare return variable.*/
String ret = "";
if(chaArr!=null)
{
/* Loop in the array. */
int len = chaArr.length;
for(int i=0;i<len;i++)
{
/* Concat the char to the return object, each operation will crate a new String object. */
char cha = chaArr[i];
/* Because each "+" action will create a new object, so this method will cost more memory and time. */
ret += cha;
}
}
System.out.println(ret);
return ret;
}
}
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