在javascript中搜索数组时忽略大小写

Question

I'm just trying to ignore case when doing a search what's the best way to do it? (No Jquery please)

function search(searchValue) {
    var found = [];
    for (var i = 0; i < photoData.length; i++) {
        if (photoData[i].description.search(searchValue) != -1) {
            found.push(photoData[i]);
        }
}
console.log(found);
return found;
}

I tried doing search(searchValue.ignoreCase) but it returns duplicates of any that have an uppercase letter. So any suggestions? I want to ignore the case of photoData's description

Answer 1

Create a new RegExp and use the case-insensitive flag, like:

function search(array, searchValue) {
    var matchedValues, re, i, j, cur;

    matchedValues = [];
    re = new RegExp(searchValue, "i");
    for (i = 0, j = array.length; i < j; i++) {
        cur = array[i];
        if (cur.description.search(re) !== -1) {
            matchedValues.push(cur);
        }
    }
    return matchedValues;
}

DEMO: http://jsfiddle.net/7veds/

Although you can use the Array.filter method also:

function search(array, searchValue) {
    var re = new RegExp(searchValue, "i");
    return array.filter(function (item, idx) {
        return item.description.search(re) !== -1;
    });
}

DEMO: http://jsfiddle.net/TKphp/

Reference:

• Array.filter : https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/filter
• RegExp : https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/RegExp#Parameters

Answer 2

As long as you're not dealing with Unicode characters (as some case conversions work unexpectedly in some Unicode supported languages), do this:

if (photoData[i].description.toUpperCase() === searchValue.toUpperCase()) {
    your code
}

or you could use toLowerCase...

Answer 3

here is a small snippet from Case insensitive search in array

function SearchArray( element, array ) {
var len = array.length, str = element.toString().toLowerCase();
for ( var i = 0; i < len; i++ ) {
    if ( array[i].toLowerCase() == str ) { return i; }
}
return -1;

}