How to sum values from Java Hashmap [duplicate]

Answer 1

You can definitely do that using a for-loop. You can either use an entry set:

for (Entry<String, Float> entry : map.entrySet()) {
    sum += entry.getValue();
}

or in this case just:

for (float value : map.values()) {
    sum += value;
}

Answer 2

If you need to add all the values in a Map, try this:

float sum = 0.0f;
for (float f : map.values()) {
    sum += f;
}

At the end, the sum variable will contain the answer. So yes, for traversing a Map's values it's best to use a for loop.

Answer 3

Float sum = 0f;
for (Float val : map.values()){
    sum += val;
}

//sum now contains the sum!

A for loop indeed serves well for the intended purpose, although you could also use a while loop and an iterator...