Offer Penalty for prove safety (string) - replace spaces

　　(Replace spaces) Title Description :

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Please implement a function, a string to replace each space to "20%." For example, when the string is We Are Happy. After the string is replaced after We% 20Are% 20Happy.

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　　Solution one: use replace function

　　Replace method call after the string str into the spaces to "% 20" can be. Note that the result of the replace method call return value is the result of type String rather than void .

public class Solution {
    public String replaceSpace(StringBuffer str) {
    	return str.toString().replace(" ", "%20");
    }
}

　　Solution two: use StringBuilder to append a new judge and results

　　char index = str.charAt (i); using this method to str through each character and with a new sbuilder receiving each character, the space in the back face append "% 20", and finally return sbuilder.toString () ;

public class Solution {
    public String replaceSpace(StringBuffer str) {
	StringBuilder sbuilder = new StringBuilder();
        for(int i=0;i<str.length();i++){
            char index = str.charAt(i);
            if(index == ' '){
                sbuilder.append("%20");
            }else{
                sbuilder.append(index);
            }
        }
        return sbuilder.toString();
	}

}