Code Organization Patterns

Module-Like Objects

Objects can group related helper functions when a small program does not need separate files.

module object A module-like object keeps related values and functions under one clear name.

Module-Like Objects

mode
module.ts
Replay: real traced execution (multi-file project)
type FormatMode = "short" | "long";

const LessonTools = {
    title(name: string): string {
        return name.trim().toUpperCase();
    },
    format(name: string, mode: FormatMode): string {
        const title: string = this.title(name);
        return mode === "long" ? `Lesson: ${title}` : title;
    },
};

const mode: FormatMode = "short";
const label: string = LessonTools.format(" typescript ", mode);

console.log(label);

type FormatMode = "short" | "long";

const LessonTools = {
    title(name: string): string {
        return name.trim().toUpperCase();
    },
    format(name: string, mode: FormatMode): string {
        const title: string = this.title(name);
        return mode === "long" ? `Lesson: ${title}` : title;
    },
};

const mode: FormatMode = "long";
const label: string = LessonTools.format(" typescript ", mode);

console.log(label);

  1. LessonTools ← [object Object], mode ← short, label ← TYPESCRIPT

    1type FormatMode = "short" | "long";23const LessonTools→ [object Object] = {4    title(name: string): string {5        return name.trim().toUpperCase();6    },7    format(name: string, mode: FormatMode): string {8        const title: string = this.title(name);9        return mode === "long" ? `Lesson: ${title}` : title;10    },11};1213const mode→ short: FormatMode = "short";  //@mode="long"14const label→ TYPESCRIPT: string = LessonTools.format(" typescript ", modeshort);1516console.log(labelTYPESCRIPT);
    outputTYPESCRIPT

  1. LessonTools ← [object Object], mode ← long, label ← Lesson: TYPESCRIPT

    1type FormatMode = "short" | "long";23const LessonTools→ [object Object] = {4    title(name: string): string {5        return name.trim().toUpperCase();6    },7    format(name: string, mode: FormatMode): string {8        const title: string = this.title(name);9        return mode === "long" ? `Lesson: ${title}` : title;10    },11};1213const mode→ long: FormatMode = "long";14const label→ Lesson: TYPESCRIPT: string = LessonTools.format(" typescript ", modelong);1516console.log(labelLesson: TYPESCRIPT);
    outputLesson: TYPESCRIPT