Functions

Default Parameters

Default parameter values let a function fill in a common value when the caller omits it.

Default Parameters

defaults.ts 
function makeLabel(text: string, prefix: string = "item"): string {
    return `${prefix}: ${text}`;
}

const labelText: string = ;
const prefixText: string = ;

const defaultLabel: string = makeLabel(labelText);
const customLabel: string = makeLabel(labelText, prefixText);

console.log(defaultLabel);
console.log(customLabel);

function makeLabel(text: string, prefix: string = "item"): string {
    return `${prefix}: ${text}`;
}

const labelText: string = ;
const prefixText: string = ;

const defaultLabel: string = makeLabel(labelText);
const customLabel: string = makeLabel(labelText, prefixText);

console.log(defaultLabel);
console.log(customLabel);

function makeLabel(text: string, prefix: string = "item"): string {
    return `${prefix}: ${text}`;
}

const labelText: string = ;
const prefixText: string = ;

const defaultLabel: string = makeLabel(labelText);
const customLabel: string = makeLabel(labelText, prefixText);

console.log(defaultLabel);
console.log(customLabel);

function makeLabel(text: string, prefix: string = "item"): string {
    return `${prefix}: ${text}`;
}

const labelText: string = ;
const prefixText: string = ;

const defaultLabel: string = makeLabel(labelText);
const customLabel: string = makeLabel(labelText, prefixText);

console.log(defaultLabel);
console.log(customLabel);

function makeLabel(text: string, prefix: string = "item"): string {
    return `${prefix}: ${text}`;
}

const labelText: string = ;
const prefixText: string = ;

const defaultLabel: string = makeLabel(labelText);
const customLabel: string = makeLabel(labelText, prefixText);

console.log(defaultLabel);
console.log(customLabel);

function makeLabel(text: string, prefix: string = "item"): string {
    return `${prefix}: ${text}`;
}

const labelText: string = ;
const prefixText: string = ;

const defaultLabel: string = makeLabel(labelText);
const customLabel: string = makeLabel(labelText, prefixText);

console.log(defaultLabel);
console.log(customLabel);

function makeLabel(text: string, prefix: string = "item"): string {
    return `${prefix}: ${text}`;
}

const labelText: string = ;
const prefixText: string = ;

const defaultLabel: string = makeLabel(labelText);
const customLabel: string = makeLabel(labelText, prefixText);

console.log(defaultLabel);
console.log(customLabel);

function makeLabel(text: string, prefix: string = "item"): string {
    return `${prefix}: ${text}`;
}

const labelText: string = ;
const prefixText: string = ;

const defaultLabel: string = makeLabel(labelText);
const customLabel: string = makeLabel(labelText, prefixText);

console.log(defaultLabel);
console.log(customLabel);

function makeLabel(text: string, prefix: string = "item"): string {
    return `${prefix}: ${text}`;
}

const labelText: string = ;
const prefixText: string = ;

const defaultLabel: string = makeLabel(labelText);
const customLabel: string = makeLabel(labelText, prefixText);

console.log(defaultLabel);
console.log(customLabel);
default parameter A parameter with `= value` uses that value when no argument is provided.