Easypt

Conditionals and loops

1. Conditional statements

In computer science, conditional statements, conditional expressions and conditional constructs are features of a programming language, which perform different computations or actions depending on whether a programmer-specified boolean condition evaluates to true or false. Apart from the case of branch predication, this is always achieved by selectively altering the control flow based on some condition.

From Wikipedia

The “if” statement is most one of most frequently used conditional statements. In Easypt if is BlockCallable method and it has following syntax:

if (condition, {
    # execute when condition is true #
});

For instance:

auto x.=("abc");
if (x.==("abc"), {
    log("x is equal to abc");
});

if also supports if-else functionality:

if (condition, {
    # execute when condition is true #
}, {
    # execute when condition is false #
});

For example:

auto a.=(6);
auto b.=(9);
if (a.>(b), {
    log("a is greater than b");
}, {
    log("a is less or equal to b");
});

2. Logical expressions

Boolean type provides few binary logical operators:

• && (AND) performs logical and, returns new Boolean
• || (OR) performs logical or, returns new Boolean
• == (in fact NEGATED XOR) compares two logical values, returns new Boolean
• != (in fact XOR) compares two logical values, returns new Boolean

and one unary logical operator:

• ! negates value of this, returns new Boolean

See in reference: Boolean

3. While loops

In most computer programming languages, a while loop is a control flow statement that allows code to be executed repeatedly based on a given Boolean condition. The while loop can be thought of as a repeating if statement.

From Wikipedia

In Easypt while is BlockCallable method and it has following syntax:

while (condition, {
    # execute while condition is true #
});

Example:

auto condition.=(true);
auto i.=(0);
while (condition, {
    log(i.++());
    if (i.==(10), { condition.=(false); });
});

4. For loops

In computer science, a for loop […] is a control flow statement for specifying iteration, which allows code to be executed repeatedly.

From Wikipedia

In Easypt for is BlockCallable method and it has following syntax (for syntax is different in Easypt than in other common languages!):

for (i.comparator, someValue, change, {
    # execute while i.comparator(someValue) is true after each iteration call change() #
});

Example of Int based for:

for (auto i.=(0).<, 10, i.++, {
    log(i);
});

Example of ArrayIterator based for:

auto arr.=(Array());
arr.pushBack(1, 7, 3.14, "abc", "def");
for (auto it.=(arr.begin()).!=, arr.end(), it.++, {
    log(it.get());
});

Example of StringIterator based for:

auto str.=("Hello world!");
for (auto it.=(str.begin()).!=, str.end(), it.++, {
    log(it.get());
});

Oops! I didn’t tell you that String has some functionality like Array (both inherits from Container, Container inherits from Iterable). String has begin and end methods and read operator ([]) as well.

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