[CC150][1.4] Write a method to replace all spaces in a string with'%20'. You may assume that the string has sufficient space at the end of the string to hold the additional characters, and that you are given the "true" length of the string. (Note: if implementing in Java, please use a character array so that you can perform this operation in pla…

replace.java

public class replace {
	
	public static String replaceBlank (String s) {
		if(s == null) return null;
		int count = 0;
		for (int i = 0; i < s.length(); i++)
			if (s.charAt(i) == ' ') count++;
		char[] newStr = new char[s.length() + count << 1];
		for (int i = 0 , j = 0; i < s.length() ; i++) {
			if (s.charAt(i) == ' ') {
				newStr[j++] = '%'; 
				newStr[j++] = '2';
				newStr[j++] = '0';
			}
			else newStr[j++] = s.charAt(i);
		}
		return new String(newStr);
	}

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		System.out.println(replace.replaceBlank(" "));
		System.out.println(replace.replaceBlank("This is Harold Finch"));
		System.out.println(replace.replaceBlank("Call me John"));
		System.out.println(replace.replaceBlank("Haha  ha"));
	}

}