freeCodeCamp/guide/english/certifications/front-end-libraries/react/change-inline-css-conditionally-based-on-component-state/index.md

title

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Change Inline CSS Conditionally Based on Component State

Change Inline CSS Conditionally Based on Component State

Hint 1:

You are going to be checking the length of this.state.input so use its .length property.

this.state.input.length

Hint 2:

You are entering code before the return statement so you can use a pure JavaScript if/then statement.

Solution:

You will use an if/then statement to check the value of this.state.input.length. If it is longer than 15, assign '3px solid red' to inputStyle.border.

class GateKeeper extends React.Component {
  constructor(props) {
    super(props);
    this.state = {
      input: ''
    };
    this.handleChange = this.handleChange.bind(this);
  }
  handleChange(event) {
    this.setState({ input: event.target.value })
  }
  render() {
    let inputStyle = {
      border: '1px solid black'
    };
    // change code below this line
    if (this.state.input.length > 15) {
      inputStyle.border = '3px solid red';
    }
    // change code above this line
    return (
      <div>
        <h3>Don't Type Too Much:</h3>
        <input
          type="text"
          style={inputStyle}
          value={this.state.input}
          onChange={this.handleChange} />
      </div>
    );
  }
};

Solution

Write a conditional statement that is evaluated according to your state, as mentioned in the challenge description, checks the length of the input and assigns a new object to the inputStyle variable.

if (this.state.input.length > 15) {
  inputStyle = {
    border: '3px solid red'
  }
}