如何獲取json stringify輸出中的特定對象？

Question

任何人都可以幫助我如何獲得json中的特定對象嗎？

我只想總結所有3在stringify輸出。

var arr_question = [{"$1z_1":3,"$2o_1":"Question 1."},{"$1z_1":3,"$2o_1":"Question2."},{"$1z_1":3,"$2o_1":"Question3."}]; 
 

 
console.log("output: "+arr_question.$1z_1); 
 
console.log("arrays: "+arr_question)

Answer 1

可以使用foreach迭代陣列之上和陣列到先前在添加的每個對象的值聲明「總」變量，它是所有值的總和。

var arr_question = [{"$1z_1":3,"$2o_1":"Question 1."},{"$1z_1":3,"$2o_1":"Question2."},{"$1z_1":3,"$2o_1":"Question3."}]; 
 

 
var total = 0; 
 
arr_question.forEach(function(obj){ 
 
    total += obj.$1z_1; 
 
}) 
 

 
console.log("output: " + total); // gives "output: 9"

Answer 2

你有對象的數組。你需要遍歷數組，訪問屬性並添加它們。一個選擇是使用reduce方法：

var arr_question = [{"$1z_1":3,"$2o_1":"Question 1."},{"$1z_1":3,"$2o_1":"Question2."},{"$1z_1":3,"$2o_1":"Question3."}]; 
 

 
console.log(
 
    "output: " + 
 
    arr_question.reduce((sum, obj) => sum + obj.$1z_1, 0) 
 
);