检查元素是否是数组中对象的属性

Question

I have a variable, for example myVariable.value = "text"

And an array of objects of this form:

[{name: "1", value: "word"},
 {name: "2", value: "text"},
 {name: "3", value: "xyz"}
]

I want to find out if myVariable.value is available as a value property of an object in the array, nothing else. Just get true if it is or false if it isn't in the array.

I found something here like:

var aa = {hello: "world"};
alert( aa["hello"] );      // popup box with "world"
alert( aa["goodbye"] );    // popup box with "undefined"

but I don't know how to do it for an array of objects. Any suggestions?

Answer 1

You can use Array#some to find the value in the array.

 let data = [{name: "1", value: "word"}, {name: "2", value: "text"}, {name: "3", value: "xyz"} ] function findValue(value) { return data.some(item => item.value === value); } console.log(findValue('text')); console.log(findValue('another')); 

Answer 2

Just get true if it is or false if it isn't in the array.

but I don't know how to do it for an array of objects. Any suggestions?

Use some and includes

var valueToFind = "text";
var isAvailable = arr.some( s => Object.values( s ).includes( valueToFind ) );

Demo

 var arr = [{ name: "1", value: "word" }, { name: "2", value: "text" }, { name: "3", value: "xyz" } ]; var valueToFind = "text"; var isAvailable = arr.some( s => Object.values(s).includes( valueToFind ) ); console.log(isAvailable); 

Convert this to a function

var fnCheckVal = ( arr, valueToFind ) => arr.some( s => Object.values(s).includes(valueToFind) );

console.log( fnCheckVal ( arr, "text" ) );
console.log( fnCheckVal ( arr, "word" ) );

Demo

 var arr = [{ name: "1", value: "word" }, { name: "2", value: "text" }, { name: "3", value: "xyz" } ]; var fnCheckVal = ( arr, valueToFind ) => arr.some( s => Object.values(s).includes(valueToFind) ); console.log( fnCheckVal ( arr, "text" ) ); console.log( fnCheckVal ( arr, "word" ) ); console.log( fnCheckVal ( arr, "valueDoesn'tExists" ) ); 

Answer 3

You can use the array find function for this kind of thing, here is an example:

 var arr = [{name: "1", value: "word"}, {name: "2", value: "text"}, {name: "3", value: "xyz"} ]; var toFind = {value: "word"}; var foundObject = arr.find(v => v.value == toFind.value); console.log(foundObject);