How do I return the object I want by using a key in a forEach loop?

Consider this code:

const year = 1910;

const items = [
 
 name: 'gallon of gas',
 year: 1910,
 price: .12
 ,
 
 name: 'gallon of gas',
 year: 1960,
 price: .30
 ,
 
 name: 'gallon of gas',
 year: 2010,
 price: 2.80
 
]

How do I display the price of the object corresponding to the year defined above?

items.forEach(d => 
 if (d.year === year) 
 return d.price;
 
);

^ Why doesn't that solution work?

edited Nov 15 '18 at 1:35

asked Nov 15 '18 at 1:30

InspectorDanno

908

forEach() doesn't return a value. Use find() instead.

– Robby Cornelissen
Nov 15 '18 at 1:32

It sounds like you are trying to only return the prices? So if that is the case, You should look up the map(fn) utility. Example: items.map( item => item.price);

– Fallenreaper
Nov 15 '18 at 1:34

1

'1910' === 1910 would return false

– Liutong Chen
Nov 15 '18 at 1:36

sorry, edited the post to make it a number.

– InspectorDanno
Nov 15 '18 at 1:36

add a comment |

Consider this code:

const year = 1910;

const items = [
 
 name: 'gallon of gas',
 year: 1910,
 price: .12
 ,
 
 name: 'gallon of gas',
 year: 1960,
 price: .30
 ,
 
 name: 'gallon of gas',
 year: 2010,
 price: 2.80
 
]

How do I display the price of the object corresponding to the year defined above?

items.forEach(d => 
 if (d.year === year) 
 return d.price;
 
);

^ Why doesn't that solution work?

edited Nov 15 '18 at 1:35

asked Nov 15 '18 at 1:30

InspectorDanno

908

forEach() doesn't return a value. Use find() instead.

– Robby Cornelissen
Nov 15 '18 at 1:32

It sounds like you are trying to only return the prices? So if that is the case, You should look up the map(fn) utility. Example: items.map( item => item.price);

– Fallenreaper
Nov 15 '18 at 1:34

1

'1910' === 1910 would return false

– Liutong Chen
Nov 15 '18 at 1:36

sorry, edited the post to make it a number.

– InspectorDanno
Nov 15 '18 at 1:36

add a comment |

Consider this code:

const year = 1910;

const items = [
 
 name: 'gallon of gas',
 year: 1910,
 price: .12
 ,
 
 name: 'gallon of gas',
 year: 1960,
 price: .30
 ,
 
 name: 'gallon of gas',
 year: 2010,
 price: 2.80
 
]

How do I display the price of the object corresponding to the year defined above?

items.forEach(d => 
 if (d.year === year) 
 return d.price;
 
);

^ Why doesn't that solution work?

edited Nov 15 '18 at 1:35

asked Nov 15 '18 at 1:30

InspectorDanno

908

Consider this code:

const year = 1910;

const items = [
 
 name: 'gallon of gas',
 year: 1910,
 price: .12
 ,
 
 name: 'gallon of gas',
 year: 1960,
 price: .30
 ,
 
 name: 'gallon of gas',
 year: 2010,
 price: 2.80
 
]

How do I display the price of the object corresponding to the year defined above?

items.forEach(d => 
 if (d.year === year) 
 return d.price;
 
);

^ Why doesn't that solution work?

javascript

edited Nov 15 '18 at 1:35

asked Nov 15 '18 at 1:30

InspectorDanno

908

edited Nov 15 '18 at 1:35

asked Nov 15 '18 at 1:30

InspectorDanno

908

edited Nov 15 '18 at 1:35

asked Nov 15 '18 at 1:30

InspectorDanno

908

asked Nov 15 '18 at 1:30

InspectorDanno

908

asked Nov 15 '18 at 1:30

InspectorDanno

908

forEach() doesn't return a value. Use find() instead.

– Robby Cornelissen
Nov 15 '18 at 1:32

It sounds like you are trying to only return the prices? So if that is the case, You should look up the map(fn) utility. Example: items.map( item => item.price);

– Fallenreaper
Nov 15 '18 at 1:34

1

'1910' === 1910 would return false

– Liutong Chen
Nov 15 '18 at 1:36

sorry, edited the post to make it a number.

– InspectorDanno
Nov 15 '18 at 1:36

add a comment |

forEach() doesn't return a value. Use find() instead.

– Robby Cornelissen
Nov 15 '18 at 1:32

It sounds like you are trying to only return the prices? So if that is the case, You should look up the map(fn) utility. Example: items.map( item => item.price);

– Fallenreaper
Nov 15 '18 at 1:34

1

'1910' === 1910 would return false

– Liutong Chen
Nov 15 '18 at 1:36

sorry, edited the post to make it a number.

– InspectorDanno
Nov 15 '18 at 1:36

forEach() doesn't return a value. Use find() instead.

– Robby Cornelissen
Nov 15 '18 at 1:32

It sounds like you are trying to only return the prices? So if that is the case, You should look up the map(fn) utility. Example: items.map( item => item.price);

– Fallenreaper
Nov 15 '18 at 1:34

'1910' === 1910 would return false

– Liutong Chen
Nov 15 '18 at 1:36

sorry, edited the post to make it a number.

– InspectorDanno
Nov 15 '18 at 1:36

add a comment |

3 Answers
3

active

oldest

votes

The forEach() function doesn't return a value, regardless of what you return in the callback function. Use find() instead to find the item that matches your criteria:

const year = '1910';

const items = [
 
 name: 'gallon of gas',
 year: 1910,
 price: .12
 ,
 
 name: 'gallon of gas',
 year: 1960,
 price: .30
 ,
 
 name: 'gallon of gas',
 year: 2010,
 price: 2.80
 
];

const item = items.find(i => i.year == year);

console.log(item.price);

Note: you can't use strict comparison (===) in the callback to find() because you're comparing a year string to a year number. Probably a good idea to address that.

answered Nov 15 '18 at 1:34

Robby Cornelissen

45k137091

add a comment |

Because that return statement is inside of the handler of the function forEach, basically, you're returning the handler execution and not the main function.

What you need to do is either to use a for-loop or the function find as follow:

let found = items.find(d => d.year === year);
if (found) return found.price;

Or a vanilla for-loop:

for (let i = 0; i < items.length; i++) 
 if (items[i].year === year) return items[i].price;

answered Nov 15 '18 at 1:34

Ele

24k52150

add a comment |

-2

This needs ES6 (babel). Hope this helps! Got it from https://zellwk.com/blog/looping-through-js-objects/.

const year = 1910;

const items = [
 
 name: 'gallon of gas',
 year: 1910,
 price: .12
 ,
 
 name: 'gallon of gas',
 year: 1960,
 price: .30
 ,
 
 name: 'gallon of gas',
 year: 2010,
 price: 2.80
 
]
const values = Object.values(items)
for (const value of values) 
 //you can't return, but you can use the value or store it in a variable/array
 console.log(value.price);

answered Nov 15 '18 at 1:40

fifn2 Confidential

368

1) Calling Object.values() on an array will just return the array, so you can get rid of that and don't need ES6. 2) Your solution prints out the prices (same as just doing items.forEach(i => console.log(i.price))), it doesn't perform a lookup based on the year as was asked in the question.

– Robby Cornelissen
Nov 15 '18 at 1:48

add a comment |

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3 Answers
3

active

oldest

votes

3 Answers
3

active

oldest

votes

The forEach() function doesn't return a value, regardless of what you return in the callback function. Use find() instead to find the item that matches your criteria:

const year = '1910';

const items = [
 
 name: 'gallon of gas',
 year: 1910,
 price: .12
 ,
 
 name: 'gallon of gas',
 year: 1960,
 price: .30
 ,
 
 name: 'gallon of gas',
 year: 2010,
 price: 2.80
 
];

const item = items.find(i => i.year == year);

console.log(item.price);

Note: you can't use strict comparison (===) in the callback to find() because you're comparing a year string to a year number. Probably a good idea to address that.

answered Nov 15 '18 at 1:34

Robby Cornelissen

45k137091

add a comment |

The forEach() function doesn't return a value, regardless of what you return in the callback function. Use find() instead to find the item that matches your criteria:

const year = '1910';

const items = [
 
 name: 'gallon of gas',
 year: 1910,
 price: .12
 ,
 
 name: 'gallon of gas',
 year: 1960,
 price: .30
 ,
 
 name: 'gallon of gas',
 year: 2010,
 price: 2.80
 
];

const item = items.find(i => i.year == year);

console.log(item.price);

Note: you can't use strict comparison (===) in the callback to find() because you're comparing a year string to a year number. Probably a good idea to address that.

answered Nov 15 '18 at 1:34

Robby Cornelissen

45k137091

add a comment |

The forEach() function doesn't return a value, regardless of what you return in the callback function. Use find() instead to find the item that matches your criteria:

const year = '1910';

const items = [
 
 name: 'gallon of gas',
 year: 1910,
 price: .12
 ,
 
 name: 'gallon of gas',
 year: 1960,
 price: .30
 ,
 
 name: 'gallon of gas',
 year: 2010,
 price: 2.80
 
];

const item = items.find(i => i.year == year);

console.log(item.price);

Note: you can't use strict comparison (===) in the callback to find() because you're comparing a year string to a year number. Probably a good idea to address that.

answered Nov 15 '18 at 1:34

Robby Cornelissen

45k137091

The forEach() function doesn't return a value, regardless of what you return in the callback function. Use find() instead to find the item that matches your criteria:

const year = '1910';

const items = [
 
 name: 'gallon of gas',
 year: 1910,
 price: .12
 ,
 
 name: 'gallon of gas',
 year: 1960,
 price: .30
 ,
 
 name: 'gallon of gas',
 year: 2010,
 price: 2.80
 
];

const item = items.find(i => i.year == year);

console.log(item.price);

Note: you can't use strict comparison (===) in the callback to find() because you're comparing a year string to a year number. Probably a good idea to address that.

const year = '1910';

const items = [
 
 name: 'gallon of gas',
 year: 1910,
 price: .12
 ,
 
 name: 'gallon of gas',
 year: 1960,
 price: .30
 ,
 
 name: 'gallon of gas',
 year: 2010,
 price: 2.80
 
];

const item = items.find(i => i.year == year);

console.log(item.price);

const year = '1910';

const items = [
 
 name: 'gallon of gas',
 year: 1910,
 price: .12
 ,
 
 name: 'gallon of gas',
 year: 1960,
 price: .30
 ,
 
 name: 'gallon of gas',
 year: 2010,
 price: 2.80
 
];

const item = items.find(i => i.year == year);

console.log(item.price);

answered Nov 15 '18 at 1:34

Robby Cornelissen

45k137091

answered Nov 15 '18 at 1:34

Robby Cornelissen

45k137091

answered Nov 15 '18 at 1:34

Robby Cornelissen

45k137091

answered Nov 15 '18 at 1:34

Robby Cornelissen

45k137091

add a comment |

Because that return statement is inside of the handler of the function forEach, basically, you're returning the handler execution and not the main function.

What you need to do is either to use a for-loop or the function find as follow:

let found = items.find(d => d.year === year);
if (found) return found.price;

Or a vanilla for-loop:

for (let i = 0; i < items.length; i++) 
 if (items[i].year === year) return items[i].price;

answered Nov 15 '18 at 1:34

Ele

24k52150

add a comment |

Because that return statement is inside of the handler of the function forEach, basically, you're returning the handler execution and not the main function.

What you need to do is either to use a for-loop or the function find as follow:

let found = items.find(d => d.year === year);
if (found) return found.price;

Or a vanilla for-loop:

for (let i = 0; i < items.length; i++) 
 if (items[i].year === year) return items[i].price;

answered Nov 15 '18 at 1:34

Ele

24k52150

add a comment |

Because that return statement is inside of the handler of the function forEach, basically, you're returning the handler execution and not the main function.

What you need to do is either to use a for-loop or the function find as follow:

let found = items.find(d => d.year === year);
if (found) return found.price;

Or a vanilla for-loop:

for (let i = 0; i < items.length; i++) 
 if (items[i].year === year) return items[i].price;

answered Nov 15 '18 at 1:34

Ele

24k52150

Because that return statement is inside of the handler of the function forEach, basically, you're returning the handler execution and not the main function.

What you need to do is either to use a for-loop or the function find as follow:

let found = items.find(d => d.year === year);
if (found) return found.price;

Or a vanilla for-loop:

for (let i = 0; i < items.length; i++) 
 if (items[i].year === year) return items[i].price;

answered Nov 15 '18 at 1:34

Ele

24k52150

answered Nov 15 '18 at 1:34

Ele

24k52150

answered Nov 15 '18 at 1:34

Ele

24k52150

answered Nov 15 '18 at 1:34

Ele

24k52150

add a comment |

-2

This needs ES6 (babel). Hope this helps! Got it from https://zellwk.com/blog/looping-through-js-objects/.

const year = 1910;

const items = [
 
 name: 'gallon of gas',
 year: 1910,
 price: .12
 ,
 
 name: 'gallon of gas',
 year: 1960,
 price: .30
 ,
 
 name: 'gallon of gas',
 year: 2010,
 price: 2.80
 
]
const values = Object.values(items)
for (const value of values) 
 //you can't return, but you can use the value or store it in a variable/array
 console.log(value.price);

answered Nov 15 '18 at 1:40

fifn2 Confidential

368

1) Calling Object.values() on an array will just return the array, so you can get rid of that and don't need ES6. 2) Your solution prints out the prices (same as just doing items.forEach(i => console.log(i.price))), it doesn't perform a lookup based on the year as was asked in the question.

– Robby Cornelissen
Nov 15 '18 at 1:48

add a comment |

-2

This needs ES6 (babel). Hope this helps! Got it from https://zellwk.com/blog/looping-through-js-objects/.

const year = 1910;

const items = [
 
 name: 'gallon of gas',
 year: 1910,
 price: .12
 ,
 
 name: 'gallon of gas',
 year: 1960,
 price: .30
 ,
 
 name: 'gallon of gas',
 year: 2010,
 price: 2.80
 
]
const values = Object.values(items)
for (const value of values) 
 //you can't return, but you can use the value or store it in a variable/array
 console.log(value.price);

answered Nov 15 '18 at 1:40

fifn2 Confidential

368

1) Calling Object.values() on an array will just return the array, so you can get rid of that and don't need ES6. 2) Your solution prints out the prices (same as just doing items.forEach(i => console.log(i.price))), it doesn't perform a lookup based on the year as was asked in the question.

– Robby Cornelissen
Nov 15 '18 at 1:48

add a comment |

-2

This needs ES6 (babel). Hope this helps! Got it from https://zellwk.com/blog/looping-through-js-objects/.

const year = 1910;

const items = [
 
 name: 'gallon of gas',
 year: 1910,
 price: .12
 ,
 
 name: 'gallon of gas',
 year: 1960,
 price: .30
 ,
 
 name: 'gallon of gas',
 year: 2010,
 price: 2.80
 
]
const values = Object.values(items)
for (const value of values) 
 //you can't return, but you can use the value or store it in a variable/array
 console.log(value.price);

answered Nov 15 '18 at 1:40

fifn2 Confidential

368

This needs ES6 (babel). Hope this helps! Got it from https://zellwk.com/blog/looping-through-js-objects/.

const year = 1910;

const items = [
 
 name: 'gallon of gas',
 year: 1910,
 price: .12
 ,
 
 name: 'gallon of gas',
 year: 1960,
 price: .30
 ,
 
 name: 'gallon of gas',
 year: 2010,
 price: 2.80
 
]
const values = Object.values(items)
for (const value of values) 
 //you can't return, but you can use the value or store it in a variable/array
 console.log(value.price);

const year = 1910;

const items = [
 
 name: 'gallon of gas',
 year: 1910,
 price: .12
 ,
 
 name: 'gallon of gas',
 year: 1960,
 price: .30
 ,
 
 name: 'gallon of gas',
 year: 2010,
 price: 2.80
 
]
const values = Object.values(items)
for (const value of values) 
 //you can't return, but you can use the value or store it in a variable/array
 console.log(value.price);

const year = 1910;

const items = [
 
 name: 'gallon of gas',
 year: 1910,
 price: .12
 ,
 
 name: 'gallon of gas',
 year: 1960,
 price: .30
 ,
 
 name: 'gallon of gas',
 year: 2010,
 price: 2.80
 
]
const values = Object.values(items)
for (const value of values) 
 //you can't return, but you can use the value or store it in a variable/array
 console.log(value.price);

answered Nov 15 '18 at 1:40

fifn2 Confidential

368

answered Nov 15 '18 at 1:40

fifn2 Confidential

368

answered Nov 15 '18 at 1:40

fifn2 Confidential

368

answered Nov 15 '18 at 1:40

fifn2 Confidential

368

1) Calling Object.values() on an array will just return the array, so you can get rid of that and don't need ES6. 2) Your solution prints out the prices (same as just doing items.forEach(i => console.log(i.price))), it doesn't perform a lookup based on the year as was asked in the question.

– Robby Cornelissen
Nov 15 '18 at 1:48

add a comment |

1) Calling Object.values() on an array will just return the array, so you can get rid of that and don't need ES6. 2) Your solution prints out the prices (same as just doing items.forEach(i => console.log(i.price))), it doesn't perform a lookup based on the year as was asked in the question.

– Robby Cornelissen
Nov 15 '18 at 1:48

1) Calling Object.values() on an array will just return the array, so you can get rid of that and don't need ES6. 2) Your solution prints out the prices (same as just doing items.forEach(i => console.log(i.price))), it doesn't perform a lookup based on the year as was asked in the question.

– Robby Cornelissen
Nov 15 '18 at 1:48

add a comment |

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