Types in Depth

Types in Depth

In this lesson — part of Data Deep Dive — you'll learn types in depth in C and why it matters in real work.

Why it matters

Types tell you what operations make sense and catch whole classes of bugs early.

Key ideas

• Common types: text, numbers, booleans
• Type conversion and coercion
• When to be explicit about types
• Type errors and how to read them

In practice

Here's how it looks in idiomatic C:

#include <stdio.h>

int main(void) {
    int    i = 7;
    double d = 3.0;
    double result = i / d;          /* int promoted to double in mixed arithmetic */
    int    truncated = (int)result; /* explicit cast: double -> int truncates */
    printf("%.4f %d\n", result, truncated);
    return 0;
}

C note: C's core types (char, int, float, double, plus unsigned/long qualifiers) convert implicitly in mixed expressions, but narrowing a double to int needs an explicit cast and silently truncates toward zero.

Try it yourself

Exercise: In C, convert a number to text and back, and print both.

Recap

You now understand types in depth and can apply it in C. Mark this lesson complete and continue to the next one.