---
id: c-data-types-reallife
title: "C Data Types Examples"
category: "Programming_Language"
status: "draft"
verification_status: "conceptual"
canonical_id: ""
aliases: ["real-life data types", "total cost calculation", "C 데이터 타입 실전 예제"]
duplicate_of: ""
source_trust_level: "B"
confidence_score: 0.83
created_at: 2026-07-04
updated_at: 2026-07-04
review_reason: ""
merge_history: []
tags: ["c", "programming-language", "w3schools", "data-types", "real-life-example"]
raw_sources: ["https://www.w3schools.com/c/c_data_types_reallife.php"]
applied_in: []
github_commit: ""
---

# [[C Data Types Examples]]

## 🎯 한 줄 통찰 (One-line insight)
This example combines THREE distinct techniques from earlier chapters into one realistic calculation — `int`×`float` multiplication implicitly producing a `float` result (`total_cost`), the `%.2f` precision control from the Decimal Precision chapter, and a `char` currency symbol printed alongside — showing that real-world numeric code is rarely a single-type operation but a composition of the type/precision/character lessons taught separately. [S1]

## 🧠 핵심 개념 (Core concepts)
- **Mixed-type arithmetic** — multiplying an `int` (`items`) by a `float` (`cost_per_item`) and storing the result in a `float` (`total_cost`). [S1]
- **Precision-controlled currency output** — using `%.2f` to show exactly two decimal places for monetary values, paired with a `char` currency symbol. [S1]
- **Calculate-then-print pattern reused** — the total is computed once and stored in a variable before being printed, consistent with the earlier Variables RealLife chapter's rectangle-area pattern. [S1]

## 📖 세부 내용 (Details)
- Full calculation and display: `int items = 50; float cost_per_item = 9.99; float total_cost = items * cost_per_item; char currency = '$'; printf("Number of items: %d\n", items); printf("Cost per item: %.2f %c\n", cost_per_item, currency); printf("Total cost = %.2f %c\n", total_cost, currency);`. [S1]

## ⚖️ 모순 및 업데이트 (Contradictions & updates)
- 현재까지 발견된 모순 사항 없음 (No contradictions found in available sources).

## 🛠️ 적용 사례 (Applied in summary)
현재 발견된 실제 적용 사례가 없습니다 — 수량(int)×단가(float)로 총 비용을 계산하고 통화 기호(char)와 함께 소수점 둘째 자리까지 출력하는 이 예제 자체가 영수증/가격 계산 UI의 실전 활용 사례다. [S1]

## 💻 코드 패턴 (Code patterns)
Combining int, float, and char types with precision control for a currency calculation (C):
```c
int items = 50;
float cost_per_item = 9.99;
float total_cost = items * cost_per_item;
char currency = '$';
printf("Total cost = %.2f %c\n", total_cost, currency);
```

## ✅ 검증 상태 및 신뢰도
- **상태:** draft
- **검증 단계:** conceptual
- **출처 신뢰도:** B (W3Schools — widely used educational reference, not a primary standards body)
- **신뢰 점수:** 0.83
- **중복 검사 결과:** 신규 생성 (New discovery)

## 🔗 지식 그래프 (Knowledge Graph)
- **상위/루트:** [[C Tutorial]]
- **관련 개념:** [[C Data Types Sizeof]], [[C Data Types Dec]], [[C Constants]]
- **참조 맥락:** 데이터 타입 섹션 마지막 — 상수 및 저장 클래스(Constants & Storage) 섹션으로 이어짐.

## 📚 출처 (Sources)
- [S1] W3Schools — C Data Types Examples — https://www.w3schools.com/c/c_data_types_reallife.php

## 📝 변경 이력 (Change history)
- 2026-07-04: Initial draft synthesized from the W3Schools "C Data Types Examples" page (Astra wiki-curation, P-Reinforce v3.1 format).
