46 lines
1.3 KiB
Java

/**
*
*/
package com.baeldung.string;
/**
* @author swpraman
*
*/
public class AppendCharAtPositionX {
public String addCharUsingCharArray(String str, char ch, int position) {
validate(str, position);
int len = str.length();
char[] updatedArr = new char[len + 1];
str.getChars(0, position, updatedArr, 0);
updatedArr[position] = ch;
str.getChars(position, len, updatedArr, position + 1);
return new String(updatedArr);
}
public String addCharUsingSubstring(String str, char ch, int position) {
validate(str, position);
return str.substring(0, position) + ch + str.substring(position);
}
public String addCharUsingStringBuilder(String str, char ch, int position) {
validate(str, position);
StringBuilder sb = new StringBuilder(str);
sb.insert(position, ch);
return sb.toString();
}
private void validate(String str, int position) {
if (str == null) {
throw new IllegalArgumentException("Str should not be null");
}
int len = str.length();
if (position < 0 || position > len) {
throw new IllegalArgumentException("position[" + position + "] should be "
+ "in the range 0.." + len + " for string " + str);
}
}
}