Ummm.... no.
Let's consider just the upper and lower-case Latin alphabet, which is a total of 52 letters. How many different 8-character strings could we make? We can choose any letter for the first, and any letter for the second, etc. Altogether there are 52^8 different strings of 8 Latin letters. That's 53459728531456 different Strings, which is
far more than the 4294967295 different values the int that hashCode() returns can hold. This means that even for such short Strings, there are an
enormous number of pairs of Strings that have the same hashCode()!
The chances that any two Strings will have the same hashCode() values is quite small. The chances that, out of a collection of Strings, two of them will have the same hashCode() are rather large! This surprising statistical result is often called the
Birthday_paradox. Did you know if you get 23 people in a room, the chances are 50-50 that two people among them share the same birthday?