array map get keyof current map code example

Example 1: array map

let A = [{ x:'x', y:'y' }, { x:'x', y:'y' }];

let result = A.map(({y,...rest})=> ({...rest,v:y}));

console.log(result);

Example 2: js map function

const exampleArray = ['aa','bbc','ccdd'];
console.log(exampleArray.map(a => a.length));
//Would print out [2,3,4]