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I did check the other questions; this question has its focus on solving this particular question the most efficient way.
Sometimes you want to create a new string with a specified length, and with a default character filling the entire string.
ie, it would be cool if you could do new String(10, '*') and create a new String from there, with a length of 10 characters all having a *.
Because such a constructor does not exist, and you cannot extend from String, you have either to create a wrapper class or a method to do this for you.
At this moment I am using this:
protected String getStringWithLengthAndFilledWithCharacter(int length, char charToFill) { char[] array = new char[length]; int pos = 0; while (pos < length) { array[pos] = charToFill; pos++; } return new String(array); } It still lacks any checking (ie, when length is 0 it will not work). I am constructing the array first because I believe it is faster than using string concatination or using a StringBuffer to do so.
Anyone else has a better sollution?
624
To define String array of specific size in Java, declare a string array and assign a new String array object to it with the size specified in the square brackets. String arrayName[] = new String[size]; //or String[] arrayName = new String[size];
To make a copy of a string, we can use the built-in new String() constructor in Java. Similarly, we can also copy it by assigning a string to the new variable, because strings are immutable objects in Java.
char Array With a for Loop. We can fill a fixed size char array with our desired character and convert that to a string: char[] charArray = new char[N]; for (int i = 0; i < N; i++) { charArray[i] = 'a'; } String newString = new String(charArray); assertEquals(EXPECTED_STRING, newString);
To display them, Java has created a special code that can be put into a string: \". Whenever this code is encountered in a string, it is replaced with a double quotation mark.
Apache Commons Lang (probably useful enough to be on the classpath of any non-trivial project) has StringUtils.repeat():
String filled = StringUtils.repeat("*", 10); Easy!
107
Simply use the StringUtils class from apache commons lang project. You have a leftPad method:
StringUtils.leftPad("foobar", 10, '*'); // Returns "****foobar" If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
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