compare to java int code example
Example 1: java integer compareto
public class IntegerCompareToExample {
public static void main(String[] args) {
Integer x = new Integer("90");
Integer y= new Integer("58");
int retResult = x.compareTo(y);
if(retResult > 0) {
System.out.println("x is greater than y");
} else if(retResult< 0) {
System.out.println("x is less than y");
} else {
System.out.println("x is equal to y");
}
}
}
Example 2: string integer compare java
num == Integer.parseInt(str) is going to faster than str.equals("" + num)
str.equals("" + num) will first convert num to string which is O(n) where n being the number of digits in the number. Then it will do a string concatenation again O(n) and then finally do the string comparison. String comparison in this case will be another O(n) - n being the number of digits in the number. So in all ~3*O(n)
num == Integer.parseInt(str) will convert the string to integer which is O(n) again where n being the number of digits in the number. And then integer comparison is O(1). So just ~1*O(n)
To summarize both are O(n) - but str.equals("" + num) has a higher constant and so is slower.