DAY_ 4. Operation -- judge whether there is a certain data in the array -- realize array mapping (enlarge by 10 times) -- insert the array in sequence (modify bugs) -- realize array de duplication

Packaging function , Determine whether there is a certain data in the array

var arr  = [7,3,24,5,20,1,0,12,10,0,5]
function hasData(arr, data) {
    
    var res = arr.indexOf(data);
    return res !=-1 ? true : false;    
}

Packaging function , Implement array mapping ( Zoom in 10 times )

function mapArr(arr) {
    
    for(var i=0;i<arr.length;i++){
    
        arr[i] = arr[i]*10;
        console.log(arr[i]);
    }
}

Algorithm implementation ：

Packaging function , Insert array in order

// Judge whether it is ascending or descending 
function fun(arr){
    
    var i =0
    while(true){
           
        if(arr[i] != arr[i+1]){
    
            return arr[i]<arr[i+1] ? true:false
        }
        i++;
    }       
}


function insert(arr, data) {
    
    if(fun(arr)){
    
        if(data>=arr[arr.length-1]){
    
            arr.push(data)
            return 0
        }
        if(data<=arr[0]){
    
            arr.unshift(data)
            return 0
        }
        for(var i=0; i< arr.length; i++){
    
            if(data >= arr[i] && data <= arr[i+1]){
    
                console.log(arr[i],arr[i+1]);
                arr.splice(i+1,0,data)
                break;
            }
        }
    }else{
    
        if(data<=arr[arr.length-1]){
    
            arr.push(data)
            return 0
        }
        if(data>=arr[0]){
    
            arr.unshift(data)
            return 0
        }
        for(var i=0; i< arr.length; i++){
    
            if(data <= arr[i] && data >= arr[i+1]){
    
                // console.log(arr[i],arr[i+1]);
                arr.splice(i+1,0,data)
                break;
            }
        }
    }
}
//var arr = [1,4,8,9,12,12]
var arr = [12,12,8,6,2,1]
insert(arr,5)
console.log(arr);
console.log(fun(arr));

=> Tips :
-> The inserted data may be the same as the internal data of the array
-> Keep the original sorting method

Implementation of array de duplication

=> explain : Consider only arrays of pure numbers
=> Tips : When you delete an item in the array , The index will collapse later
There is indeed a big hole in this one , Cautious brothers and sisters ！！！！！！（ I'm late for dinner ）

Algorithm implementation ：

var arr = [3,2,10,3,1,2,10,8,9,1,10,6,10];
console.log(arr);
//var arr = [8,1,8,8,90,90,8];
// var arr = [3,1,10,10,3,1,2];
var arr = [3,1,3,3,1,4]
console.log(arr);
var size = arr.length;
var count = 0;
for(var i=0; i<arr.length;i++){
    
    for(var j=i+1;j<arr.length;j++){
    
        if(arr[i] == arr[j]){
    
            console.log(` The current subscript of the comparison is ：${
      i}`);
            console.log(` Duplicate item ：${
      arr[j]}, Index subscript is ${
      j}`);
            arr.splice(j,1)
            console.log("=> After the current weight removal ：",arr);
            j--;
        }
        console.log(`<=======j yes ：${
      j}=========>`);
    }
}
console.log(arr);