if or condition doesn't work

I'm new to javascript and I want to run some code depending if the state.value != null or "".it doesn't throw an error but freezes there. please see my code down below.any help would be really appreciated.

constructor(){
    super();
    this.state = {
        value:null,
        list:[]
    }
}

handleList = () => {
    //let list = this.state.list.slice();
    if (this.state.value != null || this.state.value.length() > 0 ) {
        let list = [...this.state.list];
        list.push(<li>{this.state.value}</li>);

        this.setState({list});
        console.log(list.length,this.state.list.length);
    }else{
        console.log("Cant enter null");
    }
}


render() {

    return(
        <div className = 'global'>

           <button onClick={() => {this.handleList()}
            }>Add-New</button>
            <input 
                onChange = {
                    (e)=>{this.setState({value: e.target.value})}
                }
                type = 'text' 
                placeholder = 'Enter New Todo!'/>
            <hr/>
            <ul>
                {
                    this.state.list.map((li) => {
                        return (li);
                    })
                }
            </ul>

        </div>
    );
}

}