javascript - How to check for specific string in a dictionary? - Stack Overflow

admin管理员组

文章数量:1312655

I have a dictionary like:

a = {"staticData":['----','Blue','Green'], "inData":['Indatahere','----','----']}

How can I find that if the dictionary contains "----", in any of the key's values.
Any Javascript function?
EDIT: What if the case is like this?

a = {"staticData":[], "inData":['Indatahere','----','----']}

It's giving this Error:

TypeError: a[elem].indexOf is not a function

I have a dictionary like:

a = {"staticData":['----','Blue','Green'], "inData":['Indatahere','----','----']}

How can I find that if the dictionary contains "----", in any of the key's values.
Any Javascript function?
EDIT: What if the case is like this?

a = {"staticData":[], "inData":['Indatahere','----','----']}

It's giving this Error:

TypeError: a[elem].indexOf is not a function

• javascript
• function

Share Improve this question Follow edited Jul 10, 2013 at 12:43 user177800 asked Jul 10, 2013 at 10:09 MHSMHS 2,3501212 gold badges3333 silver badges4646 bronze badges 0

Add a ment  | 

4 Answers 4

Sorted by: Reset to default 2

Here is the code:

var a = {"staticData":['----','Blue','Green'], "inData":['Indatahere','----','----']};

for(var key in a){
    var value = a[key];
    for(var i=0; i<value.length; i++){
        if(value[i] == '----') alert("Found '----' in '" + key + "' at index " + i);
    };
}

EDIT: Changed iteration over array to normal way after ment.

Use indexOf to search each array in the a object:

for (elem in a)
{
    if (a[elem].indexOf("----") != -1)
       alert('---- found at ' + a[elem]);
}

EDIT For this error: TypeError: a[elem].indexOf is not a function the browser possibly considers an empty element to be a non-string type; non-string type does not have an indexOf method.

This code checks the length of the array element (if the element is empty before interpreting the indexOf function.

for (elem in a)
{
    if (a[elem].length > 0 && a[elem].indexOf("----") != -1)
       alert('---- found at ' + a[elem]);
}

If you wish to support IE < 9, see this post to conditionally add a indexOf definition to the Array object. The post also mentions a Jquery alternative.

The SO post mentioned above lists this Mozilla version of indexOf function.

if (!Array.prototype.indexOf)
{
  Array.prototype.indexOf = function(elt /*, from*/)
  {
    var len = this.length >>> 0;

    var from = Number(arguments[1]) || 0;
    from = (from < 0)
         ? Math.ceil(from)
         : Math.floor(from);
    if (from < 0)
      from += len;

    for (; from < len; from++)
    {
      if (from in this &&
          this[from] === elt)
        return from;
    }
    return -1;
  };
}

If you know exactly the nesting level of your value, then a quick solution (as suggested in other answers) is possible.

However, if you need a deep traversal search, you're gonna need a recursive version of the solutions, something like:

function FindTraverse(data, match)
{
    for (var prop in data)
    {
         if (!data.hasOwnProperty(prop)) continue;
         if (data[prop] == match) return true;
         if (typeof data[prop] == 'object' && FindTraverse(data[prop], match)) return true;
    }

    return false;
}

Examples:

FindTraverse({a:'Foo',b:'Bar'}, 'Bar') // true
FindTraverse(['Foo','Bar'], 'Bar') // true
FindTraverse([{name:'Foo'},{name:'Bar'}], 'Bar') // true
FindTraverse({a:{name:'FooBar'},b:'Bar'}, 'FooBar') // true

However, if you're looking for a more thorough solution, use a framework like jsTraverse

Use Object.getOwnPropertyNames().

You have to write two nested loops. With Object.getOwnPropertyNames you are accessing an array which consists of property names of an object. You will then need to loop over the value of those properties and identify the correct element within this second array.

a = {"staticData":['----','Blue','Green'], "inData":['Indatahere','----','----']}

props = Object.getOwnPropertyNames(a);

for (i=0;i < props.length;i ++) {
    for (z = 0; z < a[props[i]].length; z ++) {
        //console.log(a[props[i]][z])
        if ( (a[props[i]][z]) == '----') {
            console.log("I have found an item with ----")
        };
    }
}

本文标签： javascriptHow to check for specific string in a dictionaryStack Overflow