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How to write a general foreach loop in Java?

I have the following code:

/*
 * This method adds only the items that don’t already exist in the
 * ArrayCollection. If items were added return true, otherwise return false.
 */
public boolean addAll(Collection<? extends E> toBeAdded) {

    // Create a flag to see if any items were added
    boolean stuffAdded = false;


    // Use a for-each loop to go through all of the items in toBeAdded
    for (something : c) {

        // If c is already in the ArrayCollection, continue
        if (this.contains(c)) { continue; }     

            // If c isn’t already in the ArrayCollection, add it
            this.add(c)
            stuffAdded = true;
        }

        return stuffAdded;
    }
}

My question is: what am I replacing something (and c) to make this work?

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5 answers

Something like this should do:

// Use a for-each loop to go through all of the items in toBeAdded
for (E c : toBeAdded) {

    // If c is already in the ArrayCollection, continue
    if (this.contains(c)) {
        continue;
    }

    // If c isn’t already in the ArrayCollection, add it
    this.add(c);

    stuffAdded = true;
}

General form:

for (TypeOfElements iteratorVariable : collectionToBeIteratedOver) `
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E is the collection, c is the variable inside the loop for (E c: toBeAdded) ...

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foreach Java.

for(ObjectType name : iteratable/array){ name.doSomething() }

foreach , . , (Iterator), Object ObjectType. , E.

ArrayList<MyObject> al = getObjects();
for(MyObject obj : al){
  System.out.println(obj.toString());
}

:

   for(E c : toBeAdded){
        // If c is already in the ArrayCollection, continue
        if( this.contains(c) ){ continue;}     

        // If c isn’t already in the ArrayCollection, add it
        this.add(c)
        stuffAdded = true;
    }
+1
public boolean addAll(Collection<? extends E> toBeAdded) {
    boolean stuffAdded = false;
    for(E c : toBeAdded){
        if(!this.contains(c)){
             this.add(c)
             stuffAdded = true;
        }
    }
    return stuffAdded;
}

Collections.addAll

0

foreach , .

List<Integer> ints = Arrays.asList(1,2,3);
int s = 0;
for (int n : ints) { s += n; }

for (Iterator<Integer> it = ints. iterator(); it.hasNext(); ) {
    int n = it.next();
    s += n;
}
0

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