CODEWITHSUNDEEP
java
Skrmt_my
Skrmt_my

Reputation: 35

Using charAt instead of substring

public String getEncryption(String text){
    String x = "";

    for(int i = 0; i < text.length(); i++){
        String sub = text.substring(i, i+1);
        System.out.println(i + " = " + sub);
        String en = encrypt_code[Integer.parseInt(sub)];
        System.out.println("Result:" + en);
        x = x.concat(en);
    }
    return x;       
}

I have this coding which works perfectly but I need to know how to use the charAt method to convert this and works in the same way? I have this so far

public String getEncryption2(String text){
    String x = "";


    for(int i = 0; i < text.length(); i++){

        char ch = text.charAt(i);

Upvotes: 2

Views: 651

Answers (1)

JB Nizet
JB Nizet

Reputation: 691685

You're reading every char as a substring, and parse it as an int. So, you get for example "4" as the substring, and parse it to get the int 4.

If you use charAt(), you'll get the char '4' instead. To transform it to the integer 4, you just need to subtract '0' from it:

String en = encrypt_code[ch - '0'];

Note that replacing the whole string by a new one at each iteration is time consuming. You should use a StringBuilder instead:

StringBuilder x = new StringBuilder();
for (...) {
    x.append(en);
}
return x.toString();

Upvotes: 3

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