why map method won't return array items inside my span? -REACT-CodePudding

lets say we have array of object like this

dynamicField : [
{a: ['One','Two'], b: '1'},
{a: ['One'], b: '1'},
{a: ['One','Two','Three'], b: '1'}
]

i want to show all strings inside property a in a span

my code

 {dynamicField.length > 0 &&
        dynamicField.forEach((item) =>
          item[a].map((arrayItem,index) => <span key={index}>{arrayItem}</span>)
        )}

before writing <span>{arrayItem}</span> i did a console.log(arrayItem) and map method returned every item in array but it won't show it in span. what is wrong with this code?

CodePudding user response：

forEach callback doesn't return the results, you need to use two maps:

 let data = [
    {a: ['One','Two'], b: '1'},
    {a: ['One'], b: '1'},
    {a: ['One','Two','Three'], b: '1'}
    ]
    
let result = data.map(x=>x.a.map(y=>y)) // use spans in last map

console.log(result)