replace方法

 

        var str = 'hello abc abc';
        // abc替换成bbb
        let result = str.replace('abc', 'bbb')
        // let result = str.replace(/abc/g, 'bbb') // hello bbb bbb
        console.log(result); //  hello bbb abc

        // abc，保留b，b大写
        let result2 = str.replace(/a(b)(c)/g, '$1');
        console.log(result2) // hello b b
        let result1 = str.replace(/a(b)c/g, function(match, $1) {
            // console.log(args);   
            console.log(match, $1)
            return $1.toUpperCase();
        })

        console.log(result1); // hello B B