我想在React Native上制作一些坐标平面函数,但是我遇到一个问题,我不知道如何获得数组中的下一个元素。
这是我的数组:
[
{"M":["0","0"]},
{"H":"100"},
{"V":"0"},
{"H":"100"},
{"V":"100"},
{"H":"0"},
{"V":"100"},
{"H":"0"},
{"V":"0"},
]
这是我的函数:
const rotate = (pathArray, angle) =>{
if (angle > 0){
let vCordinate;
return pathArray.map((cordinate)=>{
if(Object.entries(cordinate)[0][0] == "M"){
let mCordinate = Object.entries(cordinate)[0][1];
mCordinate[0] = (parseInt(mCordinate[0]) * Math.cos(angle)) - (parseInt(mCordinate[1]) * Math.sin(angle));
mCordinate[1] = (parseInt(mCordinate[1]) * Math.cos(angle)) + (parseInt(mCordinate[0]) * Math.sin(angle));
return {[Object.entries(cordinate)[0][0]]: mCordinate};
}
//LOGIC TO GET NEXT ELEMENT
if(Object.entries(cordinate)[0][0] == "H"){
let hCordinate = Object.entries(cordinate)[0][1];
vCordinate = Object.entries(cordinate)[0][1]
return {[Object.entries(cordinate)[0][0]]: vCordinate};
}
if(Object.entries(cordinate)[0][0] == "V"){
return {[Object.entries(cordinate)[0][0]]: vCordinate};
}
})
}
return pathArray;
}
在这种情况下,当我碰到“H”时,我需要获取下一个元素。
怎么做呢?
index+1
。 - Hassan Imam