I did not understand the following line of code below:
ret += this.elem[i]+(i!=this.ultimo?", ":"");
What is the meaning of these operators i! , ? and :
{
String ret = "{";
for (int i=0; i<=this.ultimo; i++)
ret += this.elem[i]+(i!=this.ultimo?", ":"");
return ret+"}";
}
The != operator means different, or compares if i is different from this.ultimo . Example:
//i = 5
//j = 4
boolean exemplo = (i == j) //false
boolean exemplo = (j != i) //true
The operator ? is a simplified if, for example this if ..
String exemplo = "";
if (i == 1){
exemplo = "Igual a 1"
} else{
exemplo = "Diferente de 1"
}
can be simplified by:
String exemplo = (i == 1 ? "Igual a 1" : "Diferente de 1")
In other words, the operator? Tests the comparison, if true returns the value before : , if false, returns later ..
The name of this type of conditional is If ternary ( ternary operator )
Simplifying:
? == if
: == else
So if i != this.ultimo , concatene “ , “ , otherwise concatene “:”