What is the complexity of the length () function in a Java String class?

Question

This is O (n) or O (1) (By storing the length in a private variable when distributing the string for the object).

if it is O (n), does this mean that the complexity of the following code is O (n ^ 2)?

for(int i=0; i<s.length()-1;i++){
    //some code here!
}

Answer 1

This O(1)is because the length is already known to the instance String.

From JDK 1.6 it is visible.

public int length() {
    return count;
}

Answer 2

In Java, any String is created by an array final. Therefore, just simply returning the length of the array. So the complexity O(1). And if you think in your code

for(int i=0; i<s.length()-1;i++){
    //some code here!
}

s.length() , . s.length() (.. String).

Answer 3

Difficulty O(1)Since the class Stringhas a length of like field. This is not O (n ^ 2).

Answer 4

String internally supports array , and the length of the array is a property of the array object, therefore O (1) is a simple read of the property.