javascript-objects

问题 I have this sample array of objects mangoes:[ { quantity:5}, { quantity:8}, { quantity:13}, { quantity:4} ] When I remove x mangoes, that x should be subtracted from the first element in the array, and if that x exceed the first element then it should reduce the remained quantity in the second item in the array...and so forth. This is to say, I need the quantity to be reduced starting from the first one in the array down to the second if it exceed, to the third etc.. For example, If I buy 2

问题 I have this sample array of objects mangoes:[ { quantity:5}, { quantity:8}, { quantity:13}, { quantity:4} ] When I remove x mangoes, that x should be subtracted from the first element in the array, and if that x exceed the first element then it should reduce the remained quantity in the second item in the array...and so forth. This is to say, I need the quantity to be reduced starting from the first one in the array down to the second if it exceed, to the third etc.. For example, If I buy 2

问题 My use case is something like this. I have an array that has an object. That each object has an array called menu Again that menu array has objected. That each object has an array dish_has_categories In dish_has_categories array, if there is an object with CategoryId is equal to 8 I want to filter out that root object. My original data object const data = [{ menuName: "Hot dogs", menu: [ { dishId: '1', dish_has_categories: [{ CategoryId: '8' }] }, { dishId: '2', dish_has_categories: [{

问题 How do you groupBy array of objects based on specific properties in vanilla javascript? For example this given: const products = [ { category: "Sporting Goods", price: "$49.99", stocked: true, name: "Football" }, { category: "Sporting Goods", price: "$9.99", stocked: true, name: "Baseball" }, { category: "Sporting Goods", price: "$29.99", stocked: false, name: "Basketball" }, { category: "Electronics", price: "$99.99", stocked: true, name: "iPod Touch" }, { category: "Electronics", price: "

问题 How do you groupBy array of objects based on specific properties in vanilla javascript? For example this given: const products = [ { category: "Sporting Goods", price: "$49.99", stocked: true, name: "Football" }, { category: "Sporting Goods", price: "$9.99", stocked: true, name: "Baseball" }, { category: "Sporting Goods", price: "$29.99", stocked: false, name: "Basketball" }, { category: "Electronics", price: "$99.99", stocked: true, name: "iPod Touch" }, { category: "Electronics", price: "

问题 What's the best method to get the index of an object in an object array given multiple of it's properties? Imagine the following example array: var array = [ { color: 'red', shape: 'square', weight: 200 }, { color: 'blue', shape: 'circle', weight: 300 }, { color: 'red', shape: 'circle', weight: 100 } ]; Now I would like to have the indexOf the object which color property is red and shape is circle which, in this example, would be 2 . Ideally the function would return the index of the object

问题 What's the best method to get the index of an object in an object array given multiple of it's properties? Imagine the following example array: var array = [ { color: 'red', shape: 'square', weight: 200 }, { color: 'blue', shape: 'circle', weight: 300 }, { color: 'red', shape: 'circle', weight: 100 } ]; Now I would like to have the indexOf the object which color property is red and shape is circle which, in this example, would be 2 . Ideally the function would return the index of the object

问题 What's the best method to get the index of an object in an object array given multiple of it's properties? Imagine the following example array: var array = [ { color: 'red', shape: 'square', weight: 200 }, { color: 'blue', shape: 'circle', weight: 300 }, { color: 'red', shape: 'circle', weight: 100 } ]; Now I would like to have the indexOf the object which color property is red and shape is circle which, in this example, would be 2 . Ideally the function would return the index of the object

问题 I am using the following code in javascript: let group = false; let internalId = "someString"; let appliedTo = "someOtherString"; let keyToGroupBy = true === group ? internalId : appliedTo; if(grouped.hasOwnProperty([keyToGroupBy])) { ... } Could someone provide a reference as to why using the brackets with keyToGroupBy is working preferably in mdn? Is this considered a hack(works by chance) or it is something commonly used? is there a better way to do the same? 回答1: The "bracket notation" is

问题 I am using the following code in javascript: let group = false; let internalId = "someString"; let appliedTo = "someOtherString"; let keyToGroupBy = true === group ? internalId : appliedTo; if(grouped.hasOwnProperty([keyToGroupBy])) { ... } Could someone provide a reference as to why using the brackets with keyToGroupBy is working preferably in mdn? Is this considered a hack(works by chance) or it is something commonly used? is there a better way to do the same? 回答1: The "bracket notation" is