如果值包含则推送到数组

Question

Here is the code I have written

function arrayContains(value,array){
    var result = false;
    for(i=0;i<array.length;i++){
        if(array[i]==value){
            result = true;
        }
    }
    return result;
}
function someFunction(array2){
    var arr = [];
    for(i = 0 ; i<array2.length; i++){
        var val = array2[i];
        if(!arrayContains(val,arr)){
            arr.push(val);
        }
    }
    console.log(arr);
}

But, running this code, freezes the browser. What's wrong with this code?

Answer 1

You forgot var twice :

for(i=0;i<array.length;i++){

...

for(i = 0 ; i<array2.length; i++){

So all your loops use the same, global, variable i . When you call arrayContains , you reset the counter used in someFunction which leads to that infinite loop.

Be careful to add the var declaration in all your loops :

for(var i=0; i<array.length; i++){

---

Side note : you don't have to iterate over the whole array in arrayContains , you can do

function arrayContains(value, array){
    for(var i=0; i<array.length; i++){
        if(array[i]==value) return true;
    }
    return false;
}