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Learning TypeScript 2.x - Second Edition
book

Learning TypeScript 2.x - Second Edition

by Remo H. Jansen
April 2018
Beginner content levelBeginner
536 pages
13h 21m
English
Packt Publishing
Content preview from Learning TypeScript 2.x - Second Edition

Function declarations and function expressions

In the first chapter, we introduced the possibility of declaring functions with (named functions) or without (unnamed or anonymous functions) explicitly indicating their name, but we didn't mention that we were also using two different types of functions.

In the following example, the named function greetNamed is a function declaration, while greetUnnamed is a function expression. For now, please ignore the first two lines, which contain two console.log statements:

console.log(greetNamed("John")); // OK 
console.log(greetUnnamed("John")); // Error 
 
function greetNamed(name: string): string { 
    return `Hi! ${name}`; 
} 
 
let greetUnnamed = function(name: string): string { 
    return `Hi! ${name}`; 
}; 
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Publisher Resources

ISBN: 9781788391474Supplemental Content