if (condition) {

} else if (other condition) {

} else {

}

Comparison

All the comparisons below evaluate to true or false.

Equality

let x = 1;
let y = 2;

if (x == y) {
    print("x is equal to y");
} else {
    print("x is not equal to y");
}
// or
if(x!=y) {
    print("x is not equal to y");
}

Less than or Greater than

let x = 1;
let y = 2;
if (x < y) {
    print("x is less than y");
} else {
    print("x is greater than y");
}
// or
if(x > y) {
    print("x is greater than y");
}

Less than or Greater than and Equal to

let x = 1;
let y = 2;
if (x <= y) {
    print("x is less than or equal to y");
} else {
    print("x is greater than y");
}
// or
if(x >= y) {
    print("x is greater than or equal to y");
}

Logical Operators

The above conditional statements can be combined or negated using logical operators.

And Operator

for example, if you wanted to check if x is greater than y and z is less than y, you could write:

let x = 1;
let y = 2;
let z = 3;
if (x > y && z < y) {
	print("x is greater than y and z is less than y");
} else {
	print("no that did not happen");
}

Only when both conditions are true, the if block will execute. For better readability, you can use parentheses to group conditions.

let x = 1;
let y = 2;
let z = 3;
if ((x > y) && (z < y)) {
    print("x is greater than y and z is less than y");
} else {
    print("no that did not happen");
}

Sometimes you will need the parentheses to make a specific condition evaluate first or to have several and conditions evaluate together.

let x = 1;
let y = 2;
let z = 3;
if ((x > y && z < y) && (y == 10)) {
    print("x is greater than y and z is less than y and y is 10");
} else {
    print("no that did not happen");
}

Or Operator

Sometimes you have to check if one condition is true or another is true.

let x = 1;
let y = 2;
let z = 3;
if (x > y || z < y) {
	print("x is greater than y or z is less than y");
} else {
	print("no that did not happen");
}

Not Operator

The ! operator negates a condition.

let x = 1;
let y = 2;
if (!x > y) {
	print("x is not greater than y");
} else {
	print("no that did not happen");
}