CODEWITHSUNDEEP
javastringfor-loop
user3187131
user3187131

Reputation: 273

Run a for loop until the String Condition in JAVA

If I have a String array as follows.

 String[] name = {"aval", "H ---- ", "Singh", "Sawh", "Raman", " ---- ", "parminder", "kaur", "jaspreet", "asneet", " ---- "};

I want to copy all the contents from between "H ---- " to " ---- ". That is it should be "SinghSawhRaman" (excluding "H ---- " and " ---- ".

Something like this:

String keywords = "";
int j = 0;
for(int i = 0; i < name.length; i++){
 if(name[i].contains("H ---- ")){
   for(j = i; j < 5; j++){       
    // There problem is j < 5. I want to give a condition when name[i].contains(" ---- ") 
    // but not sure how should I be able to do it.
   keywords = keywords + name[j];
  }

Can someone please show me the best way to do this?

Upvotes: 1

Views: 2544

Answers (6)

Mask5323
Mask5323

Reputation: 158

String[] name = {"aval", "H ---- ", "Singh", "Sawh", "Raman", " ---- ", "parminder", "kaur", "jaspreet", "asneet", " ---- "};
String key ="";
boolean flag = false;
for(String s : name){
    if(s.equals("H ---- ")){
flag = true;
}
if(s.equals(" ---- ")){
flag = false;
}
if(flag && !s.equals("H ---- ")){
key+=s;
}
}
System.out.println(key);

Upvotes: 0

Raman
Raman

Reputation: 19635

Simply break out of the outer loop once your condition has been reached:

    boolean capture = false;
    for (String n : name) {
        if (n.contains("H ---- ")) {
            capture = true;
        } else if (n.contains(" ---- ")) {
            break;
        } else if (capture) {
            keywords = keywords + n;
        }
    }

If there are multiple occurrences of H ---- and ----, then don't break out of the loop, but simply set capture = false instead of break.

With two nested loops, you will be reading any elements that make up part of a name twice, which is inefficient. Unless it is possible to have names with nested H ----, you are better off removing the inner loop.

Upvotes: 0

Barranka
Barranka

Reputation: 21047

String keywords = "";
boolean append = false;
for(j = 0; j <= name.length; j++) {
    if(name[j].contains("H----")
        append = true;
    if(append)
        keywords += name[j];
    if(name[j].contains("----") {
        append = false;
        break;
    }
}

Notice that, if you move the if(name[j].contains("H----") block below the if(append) block, you will exclude the H--- from the keywords string;

Upvotes: 0

jzworkman
jzworkman

Reputation: 2703

  for(j = i; !name[j].contains(" ---- "); j++){   
      keywords = keywords + name[j];
  }

That should work for you, you can set the break condition of a for loop to be any boolean expression.

Edit: Need the ! in there as loop breaks when condition is false.

Upvotes: 3

Elliott Frisch
Elliott Frisch

Reputation: 201467

I would do it like so

private static String copyFrom(String[] in, String begin, String end) {
    StringBuilder sb = new StringBuilder();
    boolean start = false;
    if (in != null) {
        for (String s : in) {
            if (!start) {
                start = s.equals(begin);
            } else {
                start = !s.equals(end);
                if (start) {
                    sb.append(s);
                }
            }
        }
    }
    return sb.toString();
}

public static void main(String[] args) {
     String[] name = {"aval", "H ---- ", "Singh", "Sawh", 
                 "Raman", " ---- ", "parminder", "kaur", 
                 "jaspreet", "asneet", " ---- "};
     String keywords = copyFrom(name, "H ---- ", " ---- ");
     System.out.println(keywords);
}

Outputs

SinghSawhRaman

Upvotes: 0

user2336315
user2336315

Reputation: 16067

Any reason that you use contains instead of equals ?

If using equals is also fine for you, you could use a List :

String[] name = {"aval", "H ---- ", "Singh", "Sawh", "Raman", " ---- ", "parminder", "kaur", "jaspreet", "asneet", " ---- "};
List<String> s = Arrays.asList(name);
StringBuilder sb = new StringBuilder();
for(int i = s.indexOf("H ---- ")+1; i < s.indexOf(" ---- "); i++)
    sb.append(s.get(i));
System.out.println(sb);

Upvotes: 0

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