Question

How to loop through a set of elements in JavaScript

Answer 1

const elements = [{a:1,b:2}, {c:3,d:4}, {e:7,f:3}, {g:4,h:9}, {i:5,j:0}];

for (let i = 0; i < elements.length; i++) {
    const item = elements[i];
    console.log("index", i, "item:", item); 
}
 

 
    
/*
run:

index 0 item: { a: 1, b: 2 }
index 1 item: { c: 3, d: 4 }
index 2 item: { e: 7, f: 3 }
index 3 item: { g: 4, h: 9 }
index 4 item: { i: 5, j: 0 }

*/
 
 

 

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Answer 2

const elements = [{a:1,b:2}, {c:3,d:4}, {e:7,f:3}, {g:4,h:9}, {i:5,j:0}];

elements.forEach((item, index) => {
    console.log("index", index, "item:", item);
});

 
    
/*
run:

index 0 item: { a: 1, b: 2 }
index 1 item: { c: 3, d: 4 }
index 2 item: { e: 7, f: 3 }
index 3 item: { g: 4, h: 9 }
index 4 item: { i: 5, j: 0 }

*/
 
 

 

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Answer 3

const elements = [{a:1,b:2}, {c:3,d:4}, {e:7,f:3}, {g:4,h:9}, {i:5,j:0}];

for (let i = 0; i < elements.length; i++) {
  const item = elements[i];
  for (const key in item) {
    if (item.hasOwnProperty(key)) {
      console.log(`${key}: ${item[key]}`);
    }
  }
}

    
/*
run:

a: 1
b: 2
c: 3
d: 4
e: 7
f: 3
g: 4
h: 9
i: 5
j: 0

*/
 
 

 

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