A one-dimensional array into a two dimensional array-CodePudding

Var json=[
{
School: "college",
Title: "mathematics",
},
{
School: "college",
Title: "mathematics",
},
{
School: "school of 3",
Title: "mathematics, 2"
},
{
School: "college",
Title: "mathematics, 3"
},
]
//to heavy
Var newarr=json. The filter ((it, index)=& gt; {
Var arrids=[]
Json. ForEach ((item, I)=& gt; {
Arrids. Push (item. The title)
})
Return arrids. IndexOf (it. The title)===index
})
//search, add
Var lidev=[]
Var arr=[]
Var cent=[]
For (var I=0; i Var obj={}
Cent=[]
For (var j=0; J & lt; Json. Length; J++) {
If (newarr [I]. Title===json [j]. Title) {
Cent. Push (json [j])
}
}
Obj. Zy=cent
Obj. Title=newarr [I]. Title
Arr. Push ({obj})
}
The console. The log (arr)

CodePudding user response:

Array. The forEach (suggested) :

 
Const newArr=[], temp={}; 
Arr. ForEach (item=& gt; {
if(! \ [item. The title]) {
NewArr. Push ({obj: {title: the item title, zy: [items]}}); 
\ [item. The title]={} index: newArr. Length - 1. 
} else {
NewArr [\ [item. The title]. Index]. Obj. Zy. Push (item) 
} 
}); 
The console. The log (newArr);

Array. Reduce implementations:

 
Const result=arr. Reduce ((res: item)=& gt; {
if(! Res. \ [item. The title]) {
Res. Arr. Push ({obj: {title: the item title, zy: [items]}}); 
Res. \ [item. The title]={index: res. Arr.} to length - 1. 
} else {
Res. Arr [\ [item. The title]. Index]. Obj. Zy. Push (item) 
}; 
return res; 
}, {arr: [], temp: {}}) 
The console. The log (result. Arr);