foreach and unshift function from scratch

let cars = ["mustang","nissan-gt","hurrican","xc-90"]
//declare arr
function foreax(arr,callback)
//create a function with forloop and callback
{
for(let i=0; i<=arr.length-1;i++){
callback(arr[i],i)
}
}
//call a function
foreax(cars,(item,index) => {
console.log(${index} my name is ${item})
})

//let fruits = ["orange", "mango", "apple", "guava"]

//unshift
let car=["BMW","HONDA","POLO","MUSTANG"]

function unshiftwo(array,input)
{
for(k=array.length;k>=0;k--){
array[k] = array[k-1]
if(k==0){
array[k] = input;

}

}
}

unshiftwo(car,'rolls-royce')
console.log(car)