[Java] ArrayList → Should I specify the size in array conversion?

ArrayList<String> arrayList = new ArrayList<String>();
for(int i=0; i < 10000000;i++) { //← 100 million
	arrayList.add("A");
}
long array1Start = System.currentTimeMillis();
arrayList.toArray(new String[arrayList.size()]);              //←← here
long array1End = System.currentTimeMillis();
System.out.println("processing time:" + (array1End - array1Start) + " ms");

Processing time: 3179 ms

ArrayList<String> arrayList = new ArrayList<String>();
for(int i=0; i < 100000000;i++) { //← 100 million
	arrayList.add("A");
}
long array2Start = System.currentTimeMillis();
arrayList.toArray(new String[0]);              //←← here
long array2End = System.currentTimeMillis();
System.out.println("processing time:" + (array2End - array2Start) + " ms");

Processing time: 3047 ms

arrayList.toArray(new String[arrayList.size()]); //Explicit and easy to understand
arrayList.toArray(new String[0]);                //Think about the meaning of 0

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