Flatten List without using Flat() function in Javascript-CodePudding

I am trying to flatten a given data without using flat() function. here is my implementation

function flatten(ary) {
    var ret = [];
   
    console.log(JSON.parse(ary))
    for(var i = 0; i < ary.length; i  ) {
        if(Array.isArray(ary[i])) {
            ret = ret.concat(flatten(ary[i]));
        } else {
            ret.push(ary[i]);
        }
    }
    return ret;
}

console.log(flatten(["This is a string", 1, 2, [3], [4, [5, 6]], [[7]], 8, "[10, 11]"]));

expected output ["This is a string",1,2,3,4,5,6,7,8,10,11]

it works without the string . But when I put the string inside the argument it doesnt works.I can not use flat() function that is the main problem. Thank you

CodePudding user response：

The error you see is because you are trying to interpret This is a string as JSON. What you should do, if you want to interpret JSON values, is to try-catch the JSON.parse that way the error will be silenced. Here's the modified code.

function flatten(ary) {
    var ret = [];
   

    for(var i = 0; i < ary.length; i  ) {
        let value = ary[i];
        try{
           value = JSON.parse(value);
        }catch(e){}
        if(Array.isArray(value)) {
            ret = ret.concat(flatten(value));
        } else {
            ret.push(value);
        }
    }
    return ret;
}

console.log(flatten(["This is a string", 1, 2, [3], [4, [5, 6]], [[7]], 8, "[10, 11]"]));

CodePudding user response：

You can flatten an array like this:

function flatten(a) {
    while (a.some(Array.isArray))
        a = [].concat(...a)
    return a
}

a = ["This is a string", 1, 2, [3], [4, [5, 6]], [[7]], 8, "[10, 11]"]
console.log(flatten(a));

If there are possible json strings in the array you'd like to parse, do that beforehand, for example:

function tryParse(x) {
    try {
        return JSON.parse(x)
    } catch(e) {
        return x
    }
}

a = ["This is a string", 1, 2, [3], [4, [5, 6]], [[7]], 8, "[10, 11]"]

a = a.map(tryParse)
console.log(a)