在javascript中遍历嵌套的json文件时替换值

Question

I've searched for a long time, but cannot find any solution for my problem... I got a random nested json object like this:

var obj = { a: 1, b: 2, c: { a: 1, b: 2, c: {a: 'hello', b: 'HowAreYou?'} } };
someValue = 'hello';
newValue = 'bye';

Now I'm going to search for 'someValue'. If 'obj' contains this value the alert will be triggered. Here's my example:

function wannaChangeValue(obj) {
    var itemKey;
    if (obj instanceof Object) {
        for (itemKey in obj) {
            if (obj.hasOwnProperty(itemKey)) {
                wannaChangeValue(obj[itemKey]);
            }
        }
    } else {
        alert(obj);
        if (obj == someValue) {
            alert('got it! now change...')
            //change someValue to newValue 
        }
    }
    return obj
}

wannaChangeValue(obj)

This works really fine, but how can I change 'someValue' to 'newValue' and return the whole json-file again? I've seen many examples how to handle this, but I need a solution for ANY kind of nested json object WITHOUT knowing the path for changing this value. Maybe this is a completely wrong approach... Thanks in advance!

Answer 1

You could use a recursice approach for any found object, call the function again.

 function update(object, search, replace) { Object.keys(object).forEach(function (k) { if (object[k] && typeof object[k] === 'object') { return update(object[k], search, replace) } if (object[k] === search) { object[k] = replace; } }); } var object = { a: 1, b: 2, c: { a: 1, b: 2, c: {a: 'hello', b: 'HowAreYou?'} } }; update(object, 'hello', 'bye'); console.log(object)

 .as-console-wrapper { max-height: 100% !important; top: 0; }

Answer 2

You can create function using for...in loop and if current value match oldValue change that value.

 var obj = { a: 1, b: 2, c: { a: '1', b: 2, c: {a: 'hello', b: 'HowAreYou?'} } }; var someValue = 'hello'; var newValue = 'bye'; function changeVal(data, oldV, newV) { for(var i in data) { if(typeof data[i] == 'object') changeVal(data[i], oldV, newV); if(data[i] == oldV) data[i] = newV } return data } console.log(changeVal(obj, someValue, newValue))

Answer 3

You can define a function which search recursively the value through your object and then replace this value.

 function replaceObj (obj, valueForSearch,valueForReplace) { for (var key in obj) { var value = obj[key]; if (typeof value === 'object') { replaceObj(value, valueForSearch,valueForReplace); } if (value === valueForSearch) { obj[key]=valueForReplace; } } } let obj = { a: 1, b: 2, c: { a: 1, b: 2, c: {a: 'hello', b: 'HowAreYou?'} } }; let someValue = 'hello'; let newValue = 'bye'; replaceObj(obj,someValue,newValue); console.log(obj);

Answer 4

This is a quick solution:

function wannaChangeValue(obj) {
    var itemKey;
    if (obj instanceof Object) {
        for (itemKey in obj) {
            if (obj.hasOwnProperty(itemKey)) {
                obj[itemKey] = wannaChangeValue(obj[itemKey]);
            }
        }
    } else {
        alert(obj);
        if (obj == someValue) {
            alert('got it! now change...')
            //change someValue to newValue
            obj = someValue;
        }
    }
    return obj
}

wannaChangeValue(obj)

Obviously this will mutate the value on the object itself, so if you want an entirely new object you will have to do something different.

Answer 5

You could use recursive call for your object.

Demo

 var object = { a: 1, b: 2, c: { a: '1', b: 2, c: {a: 'hello', b: 'HowAreYou?'} } }, someValue = 'hello', newValue = 'bye'; function wannaChangeValue(obj) { var itemKey; if (obj instanceof Object) { for (itemKey in obj) { if (obj.hasOwnProperty(itemKey)) { if (!(obj[itemKey] instanceof Object) && obj[itemKey] == someValue) { //alert(someValue + ' got it! now change...') //change someValue to newValue obj[itemKey] = newValue; break; } else { wannaChangeValue(obj[itemKey]); } } } } } wannaChangeValue(object); console.log(object)

 .as-console-wrapper {max-height: 100% !important;top: 0;}

Answer 6

Here is a solution using object-scan

 // const objectScan = require('object-scan'); const obj = { a: 1, b: 2, c: { a: 1, b: 2, c: { a: 'hello', b: 'HowAreYou?' } } }; const replace = (input, oldValue, newValue) => objectScan(['**'], { abort: true, rtn: 'bool', filterFn: ({ value, parent, property }) => { if (value === oldValue) { parent[property] = newValue; return true; } return false; } })(input); console.log(replace(obj, 'hello', 'bye')); // returns true iff replace happened // => true console.log(obj); // => { a: 1, b: 2, c: { a: 1, b: 2, c: { a: 'bye', b: 'HowAreYou?' } } }

 .as-console-wrapper {max-height: 100% !important; top: 0}

 <script src="https://bundle.run/object-scan@13.7.1"></script>

Disclaimer : I'm the author of object-scan